US20070252979A1 - Binary arrays of nanoparticles for nano-enhanced raman scattering molecular sensors - Google Patents
Binary arrays of nanoparticles for nano-enhanced raman scattering molecular sensors Download PDFInfo
- Publication number
- US20070252979A1 US20070252979A1 US11/090,352 US9035205A US2007252979A1 US 20070252979 A1 US20070252979 A1 US 20070252979A1 US 9035205 A US9035205 A US 9035205A US 2007252979 A1 US2007252979 A1 US 2007252979A1
- Authority
- US
- United States
- Prior art keywords
- nanoparticles
- recited
- ners
- monolayer
- nanoparticle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/65—Raman scattering
- G01N21/658—Raman scattering enhancement Raman, e.g. surface plasmons
Definitions
- the present invention is related to an invention disclosed in an application filed Mar. 17, 2005 by Kamins et al. entitled AN ORDERED ARRAY OF NANOPARTICLES FOR EFFICIENT NANOENHANCED RAMAN SCATTERING DETECTION AND METHODS OF FORMING THE SAME.
- the present invention relates to nano-enhanced Raman spectroscopy (NERS). More particularly, the invention relates to NERS-active structures for use as analyte substrates in NERS, methods for forming NERS-active structures, NERS systems, and methods for performing NERS using NERS-active structures.
- NERS nano-enhanced Raman spectroscopy
- Raman spectroscopy is a well-known technique for analyzing molecules or materials.
- a radiation source such as a laser
- Raman spectroscopy high intensity monochromatic radiation provided by a radiation source, such as a laser
- a majority of the photons of the incident radiation are elastically scattered by the analyte.
- the scattered photons have the same energy, and thus the same wavelength, as the incident photons.
- a very small fraction of the photons typically about 1 in 10 7 , are inelastically scattered by the analyte.
- These inelastically scattered photons have a different wavelength than the incident photons. This inelastic scattering of photons is termed “Raman scattering.”
- the Raman scattered photons can have wavelengths less than, or, more typically, greater than the wavelength of the incident photons.
- the Raman scattered photon When energy is transferred from the analyte to the incident photon, the Raman scattered photon will have a higher energy and a corresponding shorter wavelength than the incident photon. These Raman scattered photons having higher energy than the incident photons are commonly referred to in Raman spectroscopy as the “anti-Stokes radiation.”
- the Stokes radiation and the anti-Stokes radiation collectively are referred to as the Raman scattered radiation or the Raman signal.
- the Raman scattered radiation is detected by a detector that typically includes a wavelength-dispersive spectrometer and a photomultiplier for converting the energy of the impinging photons into an electrical signal.
- the characteristics of the electrical signal are at least partially a function of both the energy of the Raman scattered photons as evidenced by their wavelength, frequency, or wave number, and the number of the Raman scattered photons as evidenced by the intensity of the Raman scattered radiation.
- the electrical signal generated by the detector can be used to produce a spectral graph illustrating the intensity of the Raman scattered radiation as a function of the wavelength of the Raman scattered radiation.
- Analyte molecules and materials generate unique Raman spectral graphs.
- the unique Raman spectral graph obtained by performing Raman spectroscopy can be used for many purposes including identification of an unknown analyte or determination of physical and chemical characteristics of a known analyte.
- Raman scattering of photons is a weak process.
- powerful, costly laser sources typically are used to generate high intensity incident radiation to increase the intensity of the weak Raman scattered radiation for detection.
- Surface-enhanced Raman spectroscopy is a technique that allows for enhancement of the intensity of the Raman scattered radiation relative to conventional Raman scattering.
- the analyte molecules typically are adsorbed onto or placed adjacent to a metal surface or structure. Interactions between the analyte and the metal structure cause an increase in the intensity of the Raman scattered radiation. The mechanism by which the intensity of the Raman scattered radiation is enhanced is not completely understood. Two main theories of enhancement mechanisms have been presented in the literature: electromagnetic enhancement and chemical enhancement.
- metallic structures have been employed in SERS techniques to enhance the intensity of Raman scattered radiation that is scattered by analyte molecules adjacent thereto.
- Some examples of such structures include electrodes in electrolytic cells, metal colloid solutions, and metal substrates, such as a roughened metal surface or metal “islands” formed on a substrate.
- electrodes in electrolytic cells metal colloid solutions
- metal substrates such as a roughened metal surface or metal “islands” formed on a substrate.
- adsorbing analyte molecules onto or near a specially roughened metal surface made from gold or silver can enhance the effective Raman scattering intensity by factors of between 10 3 and 10 6 , when averaged over the illuminated area of the sample.
- NERS nano-enhanced Raman spectroscopy
- NERS substrates that include metallic particles, the size, separation, and local configuration of which can be controlled to optimize the enhancement of the intensity of Raman scattered radiation by the NERS analyte substrate.
- the present invention includes a two-dimensional array of nanoparticles usable for enhancing Raman scattered radiation in NERS.
- the array of nanoparticles includes a first plurality of nanoparticles and a second plurality of nanoparticles.
- the second plurality of nanoparticles have a size and shape substantially similar to the size and shape of the first plurality of nanoparticles.
- the second plurality of nanoparticles exhibits a plasmon frequency that differs from any plasmon frequency exhibited by the first plurality of nanoparticles.
- the nanoparticles of the second plurality of nanoparticles are interspersed among the nanoparticles of the first plurality of nanoparticles in the two-dimensional array of nanoparticles.
- the present invention includes a monolayer of nanoparticles for use as a NERS-active structure.
- the monolayer of nanoparticles includes a first plurality of nanoparticles and a second plurality of nanoparticles.
- the second plurality of nanoparticles is interspersed among the first plurality of nanoparticles.
- the second plurality of nanoparticles exhibits a plasmon frequency that differs from any plasmon frequency that is exhibited by the first plurality of nanoparticles, if any.
- the concentration of the second plurality of nanoparticles in the monolayer of nanoparticles is below or near a percolation threshold.
- the present invention includes a NERS-active structure that includes a substrate, a monolayer of nanoparticles disposed on a surface of the substrate, and a spacer material partially surrounding each nanoparticle in the monolayer of nanoparticles.
- the monolayer of nanoparticles includes a first plurality of nanoparticles and a second plurality of nanoparticles.
- the second plurality of nanoparticles is interspersed among the first plurality of nanoparticles.
- the second plurality of nanoparticles exhibits a plasmon frequency that differs from any plasmon frequency that is exhibited by the first plurality of nanoparticles, if any.
- the concentration of the second plurality of nanoparticles in the monolayer of nanoparticles is below or near a percolation threshold.
- the spacer material separates each nanoparticle from adjacent nanoparticles by a selected distance.
- the spacer material covers less than the entire surface area of each nanoparticle.
- the present invention includes a NERS system that includes such a NERS-active structure.
- the NERS system further includes an excitation radiation source configured to irradiate the NERS-active structure and a detector configured to receive Raman scattered radiation scattered by an analyte located adjacent to the NERS-active structure.
- the present invention includes a method for forming a NERS-active structure.
- the method includes providing a mixture of nanoparticles including a first plurality of nanoparticles of a first material and a second plurality of nanoparticles of a second material.
- the concentration of the second plurality of nanoparticles in the mixture is less than the concentration of the first plurality of nanoparticles.
- the second plurality of nanoparticles exhibits a plasmon frequency that differs from any plasmon frequency that is exhibited by the first plurality of nanoparticles, if any.
- Each nanoparticle in the mixture of nanoparticles is coated with a spacer material.
- a monolayer of the nanoparticles is formed on a surface of a fluid and the monolayer is transferred from the surface of the fluid to a surface of the substrate by placing the substrate in contact with the monolayer of nanoparticles on the surface of the fluid. At least a portion of the spacer material is removed.
- FIG. 1 is top plan view of an exemplary embodiment of a NERS-active structure according to the invention
- FIG. 2 is a cross-sectional view of the NERS-active structure of FIG. 1 taken along section line 2 - 2 therein;
- FIGS. 3-7 illustrate an exemplary method for forming the NERS-active structure of FIGS. 1-2 ;
- FIG. 8 is a schematic diagram of an exemplary NERS system for performing nano-enhanced Raman spectroscopy using a NERS-active structure according to the invention.
- the present invention relates to nano-enhanced Raman spectroscopy (NERS). More particularly, the invention relates to NERS-active structures for use as analyte substrates in NERS, methods for forming NERS-active structures, NERS systems, and methods for performing NERS using NERS-active structures.
- NERS nano-enhanced Raman spectroscopy
- analyte as used herein means any molecule, molecules, material, substance, or matter that is to be analyzed by NERS.
- NERS-active structure means a structure that is capable of increasing the number of Raman scattered photons that are scattered by an analyte when the analyte is located adjacent to the structure and the analyte and structure are subjected to electromagnetic radiation.
- NERS-active material means a material that, when formed into appropriate geometries or configurations, is capable of increasing the number of Raman scattered photons that are scattered by an analyte when the analyte is located adjacent the material, and the analyte and material are subjected to electromagnetic radiation.
- NERS-active materials can be used to form NERS-active structures.
- nanoparticle as used herein means a particle having cross-sectional dimensions of less than about 100 nanometers.
- nanoparticles include, but are not limited to, nanodots, nanowires, nanocolumns, and nanospheres.
- percolation threshold means the critical fraction of nanoparticle sites in an array of possible nanoparticle sites that must be filled with nanoparticles to create a continuous path of adjacent nanoparticles extending from one side of a structure to another when the nanoparticle sites are filled in a random manner.
- ligand as used herein means an atom, molecule, ion or functional group that may be attached to one or more nanoparticles or to a substrate.
- polymerize means to form a generally solid structure from a liquid or gel by forming bonds between individual molecules in the liquid or gel.
- polymerize includes, for example, the formation of a network structure by forming cross-linking bonds between individual molecules, the formation of long, repeating polymer chains from small monomeric units or mers, and the formation of cross-linking bonds between long, repeating polymer chains.
- FIG. 1 is a top plan view of an exemplary NERS-active structure 10 that embodies teachings of the present invention.
- the NERS-active structure 10 includes a two-dimensional array of nanoparticles disposed on a surface of a substrate 12 .
- the two-dimensional array of nanoparticles is a binary array that includes a first plurality of inactive nanoparticles 14 and a second plurality of metallic active nanoparticles 16 .
- the first plurality of inactive nanoparticles 14 are shown by shading with dots, while the second plurality of metallic active nanoparticles 16 are shown by shading with cross-hatching.
- the metallic active nanoparticles 16 are interspersed among the inactive nanoparticles 14 .
- the plurality of inactive nanoparticles 14 also can be metallic. However, the active nanoparticles 16 exhibit a plasmon resonance frequency differing from any plasmon resonance frequency exhibited by the inactive nanoparticles 14 and should not interact in other ways with plasmons from inactive nanoparticle
- the nanoparticles 14 , 16 can have a generally spherical shape and a diameter of less than about 100 nanometers. More particularly, the nanoparticles 14 , 16 can have a diameter in a range from about 1 nanometer to about 25 nanometers, or even a range from about 1 nanometer to about 5 nanometers.
- the number of metallic active nanoparticles 16 in the two-dimensional array of nanoparticles is below or near the percolation threshold. Because the number of metallic active nanoparticles 16 is below or near the percolation threshold, isolated nanoparticles 16 , isolated pairs such as pair 18 , isolated triplets such as triplet 20 , isolated quadruplets such as quadruplet 22 , etc., of metallic active nanoparticles 16 are randomly provided in the two-dimensional array of nanoparticles 14 , 16 . These structures formed by metallic active nanoparticles 16 may be surrounded by inactive nanoparticles 14 that separate the structures from other structures formed by metallic active nanoparticles 16 .
- Nanoparticles 14 , 16 in the two-dimensional array are separated from adjacent nanoparticles 14 , 16 in the two-dimensional array by a distance X.
- the distance X can be in a range from about 1 nanometer to about 100 nanometers. More particularly, the distance X can be in a range from about 1 nanometer to about 50 nanometers, or even in a range from about 1 nanometer to about 10 nanometers.
- Each metallic active nanoparticle 16 can be formed from, for example, gold, silver, copper, or any other NERS-active material.
- Each inactive nanoparticle 14 can be formed from, for example, cobalt, silica, alumina, or any other material that either does not exhibit a plasmon resonance frequency, that exhibits a plasmon resonance frequency at a frequency differing from the plasmon resonance frequency exhibited by the metallic active nanoparticles 16 , or that otherwise does not interact with plasmons from the metallic active nanoparticles.
- the substrate 12 can be formed from, for example, silicon, silica, zirconia, alumina, tin oxides, perovskite oxides, and selected metals.
- the material used to form the substrate 12 should not exhibit a plasmon resonance frequency, or should exhibit a plasmon resonance frequency differing from the plasmon resonance frequency exhibited by the active nanoparticles 16 .
- isolated surface plasmon modes may be generated in the regions of the metallic active nanoparticles 16 when the NERS-active structure 10 is subjected to electromagnetic radiation at a particular frequency or frequencies without generating interacting surface plasmon modes in the substrate 12 .
- FIG. 2 is a cross-sectional view of the NERS-active structure 10 of FIG. 1 taken along section line 2 - 2 therein.
- the nanoparticles 14 , 16 of the two-dimensional array of nanoparticles may be at least partially covered by a spacer material 26 that separates each nanoparticle 14 , 16 from adjacent nanoparticles.
- the spacer material 26 may cover less than the entire surface area of each nanoparticle 14 , 16 in the two-dimensional array of nanoparticles 14 , 16 to allow an analyte to be adsorbed onto a portion of the surface area of the active nanoparticles 16 .
- the spacer material 26 may cover approximately the lower half of the surface area of each of the nanoparticles 14 , 16 , leaving the top halves thereof exposed.
- the spacer material 26 may include organic ligand molecules.
- the spacer material 26 may include a polymerized material.
- the spacer material 26 may bind each nanoparticle 14 , 16 in the two-dimensional array to the substrate 12 , to adjacent nanoparticles 14 , 16 , orto both the substrate 12 and adjacent nanoparticles 14 , 16 .
- Isolated pairs of nanoparticles 16 such as pair 18 , isolated triplets such as triplet 20 , and isolated quadruplets such as quadruplet 22 of NERS-active structure 10 shown in FIGS. 1-2 provide regions on the surface of the NERS-active structure 10 that vary in local configuration and allow generation of plasmon modes having different characteristics.
- the best local configuration of active nanoparticles 16 for enhancing the Raman signal typically differs for different analytes.
- the best local configuration of active nanoparticles 16 for a particular analyte typically is not known beforehand.
- the best local configuration of active nanoparticles 16 for enhancing the Raman signal for that particular analyte can be identified by determining which regions on the surface of the NERS-active structure 10 enhance the Raman scattering in the most efficient manner. The intensity of the Raman scattered radiation will be strongest at these regions.
- the two-dimensional array of nanoparticles 14 , 16 of NERS-active structure 10 may form a monolayer of nanoparticles on the surface of the substrate 12 .
- FIGS. 3-7 illustrate an exemplary method for forming the NERS-active structure 10 shown in FIGS. 1-2 that incorporates teachings of the present invention.
- the method can include use of Langmuir-Blodgett type techniques and Langmuir-Schaefer type techniques to form the monolayer of nanoparticles 14 , 16 on the surface of the substrate 12 .
- inactive nanoparticles 14 and metallic active nanoparticles 16 can be provided, and mixed together to form a mixture of nanoparticles.
- concentration of metallic active nanoparticles 16 can be sufficiently less than the concentration of inactive nanoparticles 14 in the mixture, such that when the mixture of nanoparticles 14 , 16 forms a two-dimensional monolayer array of nanoparticles, the concentration of metallic active nanoparticles 16 in the two-dimensional array is below or near the percolation threshold.
- the nanoparticles 14 , 16 may be coated with the spacer material 26 or with precursor material 26 ′ that will be used to form the spacer material 26 and provided on the surface of a fluid to form a Langmuir film.
- the nanoparticles 14 , 16 may be coated with organic ligand molecules that include a hydrophobic portion, a first functional group, and a second functional group.
- the hydrophobic portion may include, for example, an elongated alkyl chain.
- the first functional group may be used to attach the molecules of the spacer material 26 or precursor materials 26 ′ to the nanoparticles 14 , 16 and may include, for example, a thiol group.
- the second functional group may include, for example, a polymerizable vinyl group.
- the nanoparticles 14 , 16 alternatively may be coated with other molecules, such as, for example, alkane thiol HS(CH 2 )n chains with sulfur groups on one end, fluorophores, phosphate surfactants, and dendrimers. Many other molecules and functional groups are known in the art and can be used to coat the nanoparticles 14 , 16 .
- the spacer material 26 or precursor materials 26 ′ may or may not be polymerizable.
- a container 32 such as a commercially available Langmuir film trough, can be provided and filled with a fluid, such as water. Suitable Langmuir film troughs are sold by, for example, KSV Instruments of Helsinki, Finland.
- the coated nanoparticles 14 , 16 can be dissolved in a solvent and dispersed on the surface of the fluid in the container 32 with, for example, a microsyringe.
- the organic solvent can be allowed to evaporate, leaving behind the coated nanoparticles 14 , 16 on the surface of the fluid.
- the coated particles 14 , 16 may form a floating monolayer 30 of nanoparticles 14 , 16 on the surface of the fluid, as illustrated in FIG. 3 .
- Such floating monolayers 30 are often referred to as Langmuir films.
- the container 32 can include a Wilhelmy plate electrobalance for measuring the surface pressure of the floating monolayer of nanoparticles 14 , 16 , and can also include movable barriers for reducing the surface area available to the floating monolayer 30 of nanoparticles 14 , 16 on the surface of the fluid.
- a substrate 12 can be provided and placed in contact with the monolayer 30 of coated nanoparticles 14 , 16 (such as, e.g., by lowering substrate 12 into floating monolayer 30 as indicated by arrow 34 ), as shown in FIG. 4 .
- This process transfers the floating monolayer of coated nanoparticles 14 , 16 to the surface of the substrate 12 , thereby forming a two-dimensional array of nanoparticles 14 , 16 thereon.
- a substrate 12 can be passed or pulled through the monolayer of coated nanoparticles 14 , 16 .
- the monolayer of coated nanoparticles 14 , 16 may be transferred to the substrate 12 using either Langmuir Blodgeft type techniques or Langmuir-Schaefer type techniques. Movable barriers can be used to compress the floating monolayer of inactive and active nanoparticles 14 , 16 in the container 32 while the substrate is put in contact with the floating monolayer to control the ordering in the monolayer.
- the distance X shown in FIG. 1
- the distance X that separates nanoparticles 14 , 16 from adjacent nanoparticles 14 , 16 may be controlled by controlling the length or size of the molecules of the spacer material 26 or the precursor material 26 ′ surrounding the nanoparticles 14 , 16 . In this manner, the spacer material 26 may be used to separate each nanoparticle 14 , 16 in the array of nanoparticles from adjacent nanoparticles 14 , 16 by a selected distance X.
- a layer of attachment material 13 may be provided on or formed on a surface of the substrate 12 .
- the layer of attachment material 13 may be used to attach the nanoparticles 14 , 16 to the substrate 12 .
- the layer of attachment material 13 may be formed by chemically functionalizing the surface of the substrate 12 with functional groups that will adhere to the molecules of the spacer material 26 or the precursor material 26 ′.
- the surface of the substrate 12 may be functionalized by providing Si—O—H groups on a surface of the substrate 12 .
- material that will adhere to, polymerize with, or otherwise chemically bind to the spacer material 26 or the precursor material 26 ′ coating the nanoparticles 14 , 16 may be deposited on a surface of the substrate 12 to form the layer of attachment material 13 .
- the layer of attachment material 13 may adhere to and immobilize the nanoparticles 14 , 16 on a surface of the substrate 12 .
- the layer of attachment Material 13 may include the same material as the spacer material 26 or the precursor material 26 ′.
- the two-dimensional array of nanoparticles 14 , 16 may be coated with a precursor material 26 ′ that will be used to form the spacer material 26 , and the coated nanoparticles 14 , 16 may be provided on the surface of a fluid to form a Langmuir film.
- the precursor material 26 ′ and the layer of attachment material 13 each may include polymerizable functional groups, which may be polymerized to stabilize the two-dimensional array of nanoparticles 14 , 16 on the surface of the substrate 12 .
- the precursor material 26 ′ and the layer of attachment material 13 may be polymerized by processes specific to the polymerizable functional groups of the molecules of the precursor material 26 ′ and the layer of attachment material 13 .
- the precursor material 26 ′ and the layer of attachment material 13 may be subjected to radiation 40 (as illustrated in FIG. 5 ), which may cause the polymerizable functional groups of the spacer material 26 and the layer of attachment material 13 to polymerize and bind to adjacent molecules.
- a monolithic layer of spacer material 26 may be formed from the precursor material 26 ′ coating each nanoparticle 14 , 16 and the layer of attachment material 13 .
- the portion of the spacer material 26 that has been formed primarily from the precursor material 26 ′ is shown above the imaginary dividing line 44
- the portion of the spacer material 26 that has been formed primarily from the layer of attachment material 13 is shown below the imaginary dividing line 44 .
- This monolithic layer of spacer material 26 may bind the nanoparticles 14 , 16 to adjacent nanoparticles 14 , 16 and to the substrate 12 , thereby providing a solid, stable and durable structure for use as a NERS-active substrate.
- the substrate 12 may be transparent to the particular wavelengths of radiation used to allow the radiation to impinge on the spacer material 26 and the layer of attachment material 13 through the bottom of the substrate 12 .
- the spacer material 26 may include functional groups that can be bound by, for example, the addition of heat or by the addition of chemical reagents.
- the spacer material 26 may include thermoplastic material, which may be subjected to heat in order to at least partially melt the thermoplastic material coating each nanoparticle 14 , 16 . Upon cooling and re-solidification of the thermoplastic material, the thermoplastic material may stabilize the two-dimensional array of nanoparticles 14 , 16 on the surface of the substrate 12 .
- a portion of the spacer material 26 can be removed to expose at least a portion of the surface of the nanoparticles 14 , 16 .
- the portion of the spacer material 26 can be removed by, for example, an ion milling process in which high energy ions 42 are directed onto the surface of the spacer material 26 , as shown in FIG. 6 .
- a portion of the spacer material 26 can be removed by, for example, a selective wet or dry (e.g., plasma) chemical etch that removes the spacer material 26 without reacting with or otherwise affecting the nanoparticles 14 , 16 .
- Such techniques are known in the art.
- FIG. 7 is substantially similar to FIG. 2 .
- an analyte 46 upon which it is desired to perform NERS is shown disposed in the region between a first metallic active nanoparticle 16 A and a second metallic active nanoparticle 16 B.
- the first metallic active nanoparticle 16 A and the second metallic active nanoparticle 16 B together form the isolated pair 18 of FIG. 1 .
- NERS-active structures that embody teachings of the present invention such as the NERS-active structure 10 of FIGS. 1-2 can be used in NERS systems to perform NERS on an analyte.
- An exemplary NERS system 50 that embodies teachings of the present invention is illustrated schematically in FIG. 8 .
- the NERS system 50 can include a NERS-active structure embodying teachings of the invention, such as, for example, the NERS-active structure 10 of FIGS. 1-2 .
- the NERS system 50 can include a sample or analyte stage 52 for holding the NERS-active structure 10 and an analyte, an excitation radiation source 54 for providing excitation radiation 64 , and a detector 56 for detecting Raman scattered radiation 66 .
- the NERS system 50 can also include various optical components 60 such as, for example, lenses and filters positioned between the excitation radiation source 54 and the analyte stage 52 and between the analyte stage 52 and the detector 56 .
- the excitation radiation source 54 can include any suitable source for emitting radiation at the desired wavelength, and can be capable of emitting a tunable wavelength of radiation.
- any suitable source for emitting radiation at the desired wavelength can be capable of emitting a tunable wavelength of radiation.
- commercially available semiconductor lasers, helium-neon lasers, carbon dioxide lasers, radiation-emitting diodes, incandescent lamps, and many other known radiation-emitting sources can be used as the excitation radiation source 54 .
- the wavelengths that are emitted by the excitation radiation source 54 can include a suitable wavelength for performing NERS on the analyte.
- An exemplary range of wavelengths that can be emitted by the excitation radiation source 54 includes wavelengths between about 350 nanometers and about 1000 nanometers.
- the detector 56 receives and detects the Raman scattered radiation 66 generated by Raman scattered photons that are scattered by the analyte.
- the detector 56 includes a device for determining the wavelength of the Raman scattered radiation 66 such as, for example, a monochromator, and a device for determining the intensity of the Raman scattered radiation 66 such as, for example, a photomultiplier.
- the Raman scattered radiation 66 is scattered in all directions relative to the analyte stage 52 .
- the position of the detector 56 relative to the analyte stage 52 is not particularly important.
- the detector 56 can be positioned at, for example, an angle of 90° relative to the direction of the incident excitation radiation 64 to minimize the intensity of any excitation radiation 64 that is incident on the detector 56 .
- Optical components 60 positioned between the source 54 and the analyte stage 52 can be used to collimate, filter, or focus the excitation radiation 64 before the excitation radiation 54 impinges on the analyte stage 52 and the NERS-active structure 10 .
- Optical components 60 positioned between the analyte stage 52 and the detector 56 can be used to collimate, filter, or focus the Raman scattered radiation 66 .
- a filter or a plurality of filters can be employed to prevent radiation at wavelengths corresponding to the excitation radiation 64 from impinging on the detector 56 , thus allowing only the Raman scattered radiation 66 to be received by the detector 56 .
- an analyte can be provided adjacent the NERS-active structure 10 , and particularly adjacent the metallic active nanoparticles 16 .
- the NERS-active structure 10 and the analyte are then irradiated with excitation radiation 64 provided by the source 54 .
- Raman scattered radiation 66 scattered by the analyte is detected by the detector 56 .
- the NERS-active structure 10 of the analyte stage 52 may enhance the intensity of the Raman scattered radiation that is scattered by the analyte as described previously herein.
- the wavelengths and corresponding intensity of the Raman scattered radiation 66 can be determined and used to identify and provide information about the analyte.
- NERS-active structures that include metallic active nanoparticles having well controlled size, spacing, and density. These structures allow for improved nano-enhanced Raman spectroscopy and can be employed as analyte substrates that can significantly enhance the intensity of Raman scattered radiation scattered by an analyte disposed adjacent thereto.
- the performance of nanoscale electronics, optoelectronics, molecular sensors, and other devices employing the Raman effect can be improved by using the NERS-active structures disclosed herein.
Abstract
Description
- The present invention is related to an invention disclosed in an application filed Mar. 17, 2005 by Kamins et al. entitled AN ORDERED ARRAY OF NANOPARTICLES FOR EFFICIENT NANOENHANCED RAMAN SCATTERING DETECTION AND METHODS OF FORMING THE SAME.
- The present invention relates to nano-enhanced Raman spectroscopy (NERS). More particularly, the invention relates to NERS-active structures for use as analyte substrates in NERS, methods for forming NERS-active structures, NERS systems, and methods for performing NERS using NERS-active structures.
- Raman spectroscopy is a well-known technique for analyzing molecules or materials. In conventional Raman spectroscopy, high intensity monochromatic radiation provided by a radiation source, such as a laser, is directed onto an analyte (or sample) that is to be analyzed. A majority of the photons of the incident radiation are elastically scattered by the analyte. In other words, the scattered photons have the same energy, and thus the same wavelength, as the incident photons. However, a very small fraction of the photons, typically about 1 in 107, are inelastically scattered by the analyte. These inelastically scattered photons have a different wavelength than the incident photons. This inelastic scattering of photons is termed “Raman scattering.” The Raman scattered photons can have wavelengths less than, or, more typically, greater than the wavelength of the incident photons.
- When an incident photon collides with the analyte, energy can be transferred from the photon to the molecules or atoms of the analyte, or from the molecules or atoms of the analyte to the photon. When energy is transferred from the incident photon to the analyte, the Raman scattered photon will have a lower energy and a corresponding longer wavelength than the incident photon. These Raman scattered photons having lower energy than the incident photons are collectively referred to in Raman spectroscopy as the “Stokes radiation.” A small fraction of the analyte molecules or atoms can be in an energetically excited state when photons are incident thereon. When energy is transferred from the analyte to the incident photon, the Raman scattered photon will have a higher energy and a corresponding shorter wavelength than the incident photon. These Raman scattered photons having higher energy than the incident photons are commonly referred to in Raman spectroscopy as the “anti-Stokes radiation.” The Stokes radiation and the anti-Stokes radiation collectively are referred to as the Raman scattered radiation or the Raman signal.
- The Raman scattered radiation is detected by a detector that typically includes a wavelength-dispersive spectrometer and a photomultiplier for converting the energy of the impinging photons into an electrical signal. The characteristics of the electrical signal are at least partially a function of both the energy of the Raman scattered photons as evidenced by their wavelength, frequency, or wave number, and the number of the Raman scattered photons as evidenced by the intensity of the Raman scattered radiation. The electrical signal generated by the detector can be used to produce a spectral graph illustrating the intensity of the Raman scattered radiation as a function of the wavelength of the Raman scattered radiation. Analyte molecules and materials generate unique Raman spectral graphs. The unique Raman spectral graph obtained by performing Raman spectroscopy can be used for many purposes including identification of an unknown analyte or determination of physical and chemical characteristics of a known analyte.
- Raman scattering of photons is a weak process. As a result, powerful, costly laser sources typically are used to generate high intensity incident radiation to increase the intensity of the weak Raman scattered radiation for detection. Surface-enhanced Raman spectroscopy (SERS) is a technique that allows for enhancement of the intensity of the Raman scattered radiation relative to conventional Raman scattering. In SERS, the analyte molecules typically are adsorbed onto or placed adjacent to a metal surface or structure. Interactions between the analyte and the metal structure cause an increase in the intensity of the Raman scattered radiation. The mechanism by which the intensity of the Raman scattered radiation is enhanced is not completely understood. Two main theories of enhancement mechanisms have been presented in the literature: electromagnetic enhancement and chemical enhancement. For further discussion of these enhancement mechanism theories, see A. M. Michaels, M. Nirmal, & L. E. Brus, “Surface Enhanced Raman Spectroscopy of Individual Rhodamine 6G Molecules on Large Ag Nanocrystals,” J. Am. Chem. Soc. 121, 9932-39 (1999).
- Several types of metallic structures have been employed in SERS techniques to enhance the intensity of Raman scattered radiation that is scattered by analyte molecules adjacent thereto. Some examples of such structures include electrodes in electrolytic cells, metal colloid solutions, and metal substrates, such as a roughened metal surface or metal “islands” formed on a substrate. For example, it has been shown that adsorbing analyte molecules onto or near a specially roughened metal surface made from gold or silver can enhance the effective Raman scattering intensity by factors of between 103 and 106, when averaged over the illuminated area of the sample.
- Recently, SERS has been performed employing randomly oriented nanometer-scale metallic needles and particles, as opposed to a simple roughened metallic surface. This process will be referred to hereinafter as nano-enhanced Raman spectroscopy (NERS). The intensity of the Raman scattered photons from a molecule adsorbed on such a metal surface can be increased by factors as high as 1016. At this level of sensitivity, NERS has been used to detect single molecules. Detecting single molecules with high sensitivity and molecular specificity is of great interest in the fields of chemistry, biology, medicine, pharmacology, and environmental science. However, it is unknown what configurations, including size, shape and spacing, of metallic particles will enhance the intensity of Raman scattered radiation most effectively.
- Accordingly, there is a need for NERS substrates that include metallic particles, the size, separation, and local configuration of which can be controlled to optimize the enhancement of the intensity of Raman scattered radiation by the NERS analyte substrate.
- In one aspect, the present invention includes a two-dimensional array of nanoparticles usable for enhancing Raman scattered radiation in NERS. The array of nanoparticles includes a first plurality of nanoparticles and a second plurality of nanoparticles. The second plurality of nanoparticles have a size and shape substantially similar to the size and shape of the first plurality of nanoparticles. The second plurality of nanoparticles exhibits a plasmon frequency that differs from any plasmon frequency exhibited by the first plurality of nanoparticles. The nanoparticles of the second plurality of nanoparticles are interspersed among the nanoparticles of the first plurality of nanoparticles in the two-dimensional array of nanoparticles.
- In another aspect, the present invention includes a monolayer of nanoparticles for use as a NERS-active structure. The monolayer of nanoparticles includes a first plurality of nanoparticles and a second plurality of nanoparticles. The second plurality of nanoparticles is interspersed among the first plurality of nanoparticles. The second plurality of nanoparticles exhibits a plasmon frequency that differs from any plasmon frequency that is exhibited by the first plurality of nanoparticles, if any. The concentration of the second plurality of nanoparticles in the monolayer of nanoparticles is below or near a percolation threshold.
- In another aspect, the present invention includes a NERS-active structure that includes a substrate, a monolayer of nanoparticles disposed on a surface of the substrate, and a spacer material partially surrounding each nanoparticle in the monolayer of nanoparticles. The monolayer of nanoparticles includes a first plurality of nanoparticles and a second plurality of nanoparticles. The second plurality of nanoparticles is interspersed among the first plurality of nanoparticles. The second plurality of nanoparticles exhibits a plasmon frequency that differs from any plasmon frequency that is exhibited by the first plurality of nanoparticles, if any. The concentration of the second plurality of nanoparticles in the monolayer of nanoparticles is below or near a percolation threshold. The spacer material separates each nanoparticle from adjacent nanoparticles by a selected distance. The spacer material covers less than the entire surface area of each nanoparticle.
- In yet another aspect, the present invention includes a NERS system that includes such a NERS-active structure. The NERS system further includes an excitation radiation source configured to irradiate the NERS-active structure and a detector configured to receive Raman scattered radiation scattered by an analyte located adjacent to the NERS-active structure.
- In another aspect, the present invention includes a method for forming a NERS-active structure. The method includes providing a mixture of nanoparticles including a first plurality of nanoparticles of a first material and a second plurality of nanoparticles of a second material. The concentration of the second plurality of nanoparticles in the mixture is less than the concentration of the first plurality of nanoparticles. The second plurality of nanoparticles exhibits a plasmon frequency that differs from any plasmon frequency that is exhibited by the first plurality of nanoparticles, if any. Each nanoparticle in the mixture of nanoparticles is coated with a spacer material. A monolayer of the nanoparticles is formed on a surface of a fluid and the monolayer is transferred from the surface of the fluid to a surface of the substrate by placing the substrate in contact with the monolayer of nanoparticles on the surface of the fluid. At least a portion of the spacer material is removed.
- The features, advantages, and alternative aspects of the present invention will be apparent to those skilled in the art from a consideration of the following detailed description taken in combination with the accompanying drawings.
- While the specification concludes with claims particularly pointing out and distinctly claiming that which is regarded as the present invention, the advantages of this invention can be more readily ascertained from the following description of the invention when read in conjunction with the accompanying drawings in which:
-
FIG. 1 is top plan view of an exemplary embodiment of a NERS-active structure according to the invention; -
FIG. 2 is a cross-sectional view of the NERS-active structure ofFIG. 1 taken along section line 2-2 therein; -
FIGS. 3-7 illustrate an exemplary method for forming the NERS-active structure ofFIGS. 1-2 ; and -
FIG. 8 is a schematic diagram of an exemplary NERS system for performing nano-enhanced Raman spectroscopy using a NERS-active structure according to the invention. - The present invention relates to nano-enhanced Raman spectroscopy (NERS). More particularly, the invention relates to NERS-active structures for use as analyte substrates in NERS, methods for forming NERS-active structures, NERS systems, and methods for performing NERS using NERS-active structures.
- The term “analyte” as used herein means any molecule, molecules, material, substance, or matter that is to be analyzed by NERS.
- The term “NERS-active structure” as used herein means a structure that is capable of increasing the number of Raman scattered photons that are scattered by an analyte when the analyte is located adjacent to the structure and the analyte and structure are subjected to electromagnetic radiation.
- The term “NERS-active material” as used herein means a material that, when formed into appropriate geometries or configurations, is capable of increasing the number of Raman scattered photons that are scattered by an analyte when the analyte is located adjacent the material, and the analyte and material are subjected to electromagnetic radiation. NERS-active materials can be used to form NERS-active structures.
- The term “nanoparticle” as used herein means a particle having cross-sectional dimensions of less than about 100 nanometers. Examples of nanoparticles include, but are not limited to, nanodots, nanowires, nanocolumns, and nanospheres.
- The term “percolation threshold” as used herein means the critical fraction of nanoparticle sites in an array of possible nanoparticle sites that must be filled with nanoparticles to create a continuous path of adjacent nanoparticles extending from one side of a structure to another when the nanoparticle sites are filled in a random manner.
- The term “ligand” as used herein means an atom, molecule, ion or functional group that may be attached to one or more nanoparticles or to a substrate.
- The term “polymerize” as used herein means to form a generally solid structure from a liquid or gel by forming bonds between individual molecules in the liquid or gel. The term “polymerize” as used herein includes, for example, the formation of a network structure by forming cross-linking bonds between individual molecules, the formation of long, repeating polymer chains from small monomeric units or mers, and the formation of cross-linking bonds between long, repeating polymer chains.
- The illustrations presented herein are not meant to be actual views of any particular NERS-active structure, but are merely idealized representations which are employed to describe the present invention. Additionally, elements common between figures retain the same numerical designation.
-
FIG. 1 is a top plan view of an exemplary NERS-active structure 10 that embodies teachings of the present invention. The NERS-active structure 10 includes a two-dimensional array of nanoparticles disposed on a surface of asubstrate 12. The two-dimensional array of nanoparticles is a binary array that includes a first plurality ofinactive nanoparticles 14 and a second plurality of metallicactive nanoparticles 16. The first plurality ofinactive nanoparticles 14 are shown by shading with dots, while the second plurality of metallicactive nanoparticles 16 are shown by shading with cross-hatching. The metallicactive nanoparticles 16 are interspersed among theinactive nanoparticles 14. The plurality ofinactive nanoparticles 14 also can be metallic. However, theactive nanoparticles 16 exhibit a plasmon resonance frequency differing from any plasmon resonance frequency exhibited by theinactive nanoparticles 14 and should not interact in other ways with plasmons frominactive nanoparticles 14. - The
nanoparticles nanoparticles - The number of metallic
active nanoparticles 16 in the two-dimensional array of nanoparticles is below or near the percolation threshold. Because the number of metallicactive nanoparticles 16 is below or near the percolation threshold,isolated nanoparticles 16, isolated pairs such aspair 18, isolated triplets such astriplet 20, isolated quadruplets such asquadruplet 22, etc., of metallicactive nanoparticles 16 are randomly provided in the two-dimensional array ofnanoparticles active nanoparticles 16 may be surrounded byinactive nanoparticles 14 that separate the structures from other structures formed by metallicactive nanoparticles 16. -
Nanoparticles adjacent nanoparticles - Each metallic
active nanoparticle 16 can be formed from, for example, gold, silver, copper, or any other NERS-active material. Eachinactive nanoparticle 14 can be formed from, for example, cobalt, silica, alumina, or any other material that either does not exhibit a plasmon resonance frequency, that exhibits a plasmon resonance frequency at a frequency differing from the plasmon resonance frequency exhibited by the metallicactive nanoparticles 16, or that otherwise does not interact with plasmons from the metallic active nanoparticles. This allows isolated surface plasmon modes to be generated in the regions of the metallicactive nanoparticles 16 when the NERS-active structure 10 is subjected to electromagnetic radiation at a particular frequency or frequencies without generating interacting surface plasmon modes in the regions of theinactive nanoparticles 14. - The
substrate 12 can be formed from, for example, silicon, silica, zirconia, alumina, tin oxides, perovskite oxides, and selected metals. The material used to form thesubstrate 12 should not exhibit a plasmon resonance frequency, or should exhibit a plasmon resonance frequency differing from the plasmon resonance frequency exhibited by theactive nanoparticles 16. In this configuration, isolated surface plasmon modes may be generated in the regions of the metallicactive nanoparticles 16 when the NERS-active structure 10 is subjected to electromagnetic radiation at a particular frequency or frequencies without generating interacting surface plasmon modes in thesubstrate 12. -
FIG. 2 is a cross-sectional view of the NERS-active structure 10 ofFIG. 1 taken along section line 2-2 therein. As seen inFIG. 2 , thenanoparticles spacer material 26 that separates eachnanoparticle spacer material 26 may cover less than the entire surface area of eachnanoparticle nanoparticles active nanoparticles 16. Thespacer material 26 may cover approximately the lower half of the surface area of each of thenanoparticles spacer material 26 may include organic ligand molecules. In another embodiment of the invention, thespacer material 26 may include a polymerized material. Furthermore, thespacer material 26 may bind eachnanoparticle substrate 12, toadjacent nanoparticles substrate 12 andadjacent nanoparticles - Isolated pairs of
nanoparticles 16 such aspair 18, isolated triplets such astriplet 20, and isolated quadruplets such asquadruplet 22 of NERS-active structure 10 shown inFIGS. 1-2 provide regions on the surface of the NERS-active structure 10 that vary in local configuration and allow generation of plasmon modes having different characteristics. The best local configuration ofactive nanoparticles 16 for enhancing the Raman signal typically differs for different analytes. In addition, the best local configuration ofactive nanoparticles 16 for a particular analyte typically is not known beforehand. When an analyte is adsorbed on the surface of NERS-active structure 10 and enhanced Raman spectroscopy is performed, the best local configuration ofactive nanoparticles 16 for enhancing the Raman signal for that particular analyte can be identified by determining which regions on the surface of the NERS-active structure 10 enhance the Raman scattering in the most efficient manner. The intensity of the Raman scattered radiation will be strongest at these regions. - As seen in
FIG. 2 , the two-dimensional array ofnanoparticles active structure 10 may form a monolayer of nanoparticles on the surface of thesubstrate 12. -
FIGS. 3-7 illustrate an exemplary method for forming the NERS-active structure 10 shown inFIGS. 1-2 that incorporates teachings of the present invention. The method can include use of Langmuir-Blodgett type techniques and Langmuir-Schaefer type techniques to form the monolayer ofnanoparticles substrate 12. - Commercially available
inactive nanoparticles 14 and metallicactive nanoparticles 16 can be provided, and mixed together to form a mixture of nanoparticles. The concentration of metallicactive nanoparticles 16 can be sufficiently less than the concentration ofinactive nanoparticles 14 in the mixture, such that when the mixture ofnanoparticles active nanoparticles 16 in the two-dimensional array is below or near the percolation threshold. - As shown in
FIG. 3 , thenanoparticles spacer material 26 or withprecursor material 26′ that will be used to form thespacer material 26 and provided on the surface of a fluid to form a Langmuir film. For example, thenanoparticles spacer material 26 orprecursor materials 26′ to thenanoparticles nanoparticles nanoparticles spacer material 26 orprecursor materials 26′ may or may not be polymerizable. - A
container 32, such as a commercially available Langmuir film trough, can be provided and filled with a fluid, such as water. Suitable Langmuir film troughs are sold by, for example, KSV Instruments of Helsinki, Finland. Thecoated nanoparticles container 32 with, for example, a microsyringe. The organic solvent can be allowed to evaporate, leaving behind thecoated nanoparticles coated particles spacer material 26 orprecursor material 26′ that include molecules having a hydrophobic portion thereof, thecoated particles monolayer 30 ofnanoparticles FIG. 3 . Such floatingmonolayers 30 are often referred to as Langmuir films. Thecontainer 32 can include a Wilhelmy plate electrobalance for measuring the surface pressure of the floating monolayer ofnanoparticles monolayer 30 ofnanoparticles - A
substrate 12 can be provided and placed in contact with themonolayer 30 ofcoated nanoparticles 14, 16 (such as, e.g., by loweringsubstrate 12 into floatingmonolayer 30 as indicated by arrow 34), as shown inFIG. 4 . This process transfers the floating monolayer ofcoated nanoparticles substrate 12, thereby forming a two-dimensional array ofnanoparticles substrate 12 can be passed or pulled through the monolayer ofcoated nanoparticles coated nanoparticles substrate 12 using either Langmuir Blodgeft type techniques or Langmuir-Schaefer type techniques. Movable barriers can be used to compress the floating monolayer of inactive andactive nanoparticles container 32 while the substrate is put in contact with the floating monolayer to control the ordering in the monolayer. The distance X (shown inFIG. 1 ) that separatesnanoparticles adjacent nanoparticles spacer material 26 or theprecursor material 26′ surrounding thenanoparticles spacer material 26 may be used to separate eachnanoparticle adjacent nanoparticles - As shown in
FIG. 4 , a layer ofattachment material 13 may be provided on or formed on a surface of thesubstrate 12. The layer ofattachment material 13 may be used to attach thenanoparticles substrate 12. For example, the layer ofattachment material 13 may be formed by chemically functionalizing the surface of thesubstrate 12 with functional groups that will adhere to the molecules of thespacer material 26 or theprecursor material 26′. For example, the surface of thesubstrate 12 may be functionalized by providing Si—O—H groups on a surface of thesubstrate 12. Alternatively, material that will adhere to, polymerize with, or otherwise chemically bind to thespacer material 26 or theprecursor material 26′ coating thenanoparticles substrate 12 to form the layer ofattachment material 13. In this manner, the layer ofattachment material 13 may adhere to and immobilize thenanoparticles substrate 12. Furthermore, the layer ofattachment Material 13 may include the same material as thespacer material 26 or theprecursor material 26′. - In one particular embodiment of the invention, the two-dimensional array of
nanoparticles precursor material 26′ that will be used to form thespacer material 26, and thecoated nanoparticles precursor material 26′ and the layer ofattachment material 13 each may include polymerizable functional groups, which may be polymerized to stabilize the two-dimensional array ofnanoparticles substrate 12. Theprecursor material 26′ and the layer ofattachment material 13 may be polymerized by processes specific to the polymerizable functional groups of the molecules of theprecursor material 26′ and the layer ofattachment material 13. - For example, the
precursor material 26′ and the layer ofattachment material 13 may be subjected to radiation 40 (as illustrated inFIG. 5 ), which may cause the polymerizable functional groups of thespacer material 26 and the layer ofattachment material 13 to polymerize and bind to adjacent molecules. As shown inFIG. 6 , in this manner, a monolithic layer ofspacer material 26 may be formed from theprecursor material 26′ coating eachnanoparticle attachment material 13. InFIG. 6 , the portion of thespacer material 26 that has been formed primarily from theprecursor material 26′ is shown above theimaginary dividing line 44, while the portion of thespacer material 26 that has been formed primarily from the layer ofattachment material 13 is shown below theimaginary dividing line 44. This monolithic layer ofspacer material 26 may bind thenanoparticles adjacent nanoparticles substrate 12, thereby providing a solid, stable and durable structure for use as a NERS-active substrate. - If
radiation 40 will be used to polymerize or cross-link thespacer material 26 and the layer ofattachment material 13, thesubstrate 12 may be transparent to the particular wavelengths of radiation used to allow the radiation to impinge on thespacer material 26 and the layer ofattachment material 13 through the bottom of thesubstrate 12. Alternatively, thespacer material 26 may include functional groups that can be bound by, for example, the addition of heat or by the addition of chemical reagents. - In another embodiment, the
spacer material 26 may include thermoplastic material, which may be subjected to heat in order to at least partially melt the thermoplastic material coating eachnanoparticle nanoparticles substrate 12. - A portion of the
spacer material 26 can be removed to expose at least a portion of the surface of thenanoparticles spacer material 26 can be removed by, for example, an ion milling process in whichhigh energy ions 42 are directed onto the surface of thespacer material 26, as shown inFIG. 6 . Alternatively, a portion of thespacer material 26 can be removed by, for example, a selective wet or dry (e.g., plasma) chemical etch that removes thespacer material 26 without reacting with or otherwise affecting thenanoparticles - Removing a portion of the
spacer material 26 produces the NERS-active structure 10 shown inFIG. 7 .FIG. 7 is substantially similar toFIG. 2 . However, ananalyte 46 upon which it is desired to perform NERS is shown disposed in the region between a first metallicactive nanoparticle 16A and a second metallicactive nanoparticle 16B. The first metallicactive nanoparticle 16A and the second metallicactive nanoparticle 16B together form theisolated pair 18 ofFIG. 1 . When the NERS-active structure 10 is subjected to electromagnetic radiation having a frequency that corresponds to the plasmon resonance frequency exhibited by the metallicactive nanoparticles 16, large gradients in the electric field can be produced at the region between the first activemetallic nanoparticle 16A and the second activemetallic nanoparticle 16B ofisolated pair 18. These gradients have been shown to enhance the Raman scattering of photons by an analyte when the analyte is disposed in and subjected to these gradients in the electromagnetic fields. Similar gradients in the electric field also may be generated in the regions of isolated triplets such astriplet 20, isolated quadruplets such asquadruplet 22, etc. - NERS-active structures that embody teachings of the present invention such as the NERS-
active structure 10 ofFIGS. 1-2 can be used in NERS systems to perform NERS on an analyte. Anexemplary NERS system 50 that embodies teachings of the present invention is illustrated schematically inFIG. 8 . TheNERS system 50 can include a NERS-active structure embodying teachings of the invention, such as, for example, the NERS-active structure 10 ofFIGS. 1-2 . TheNERS system 50 can include a sample oranalyte stage 52 for holding the NERS-active structure 10 and an analyte, anexcitation radiation source 54 for providingexcitation radiation 64, and adetector 56 for detecting Raman scatteredradiation 66. TheNERS system 50 can also include variousoptical components 60 such as, for example, lenses and filters positioned between theexcitation radiation source 54 and theanalyte stage 52 and between theanalyte stage 52 and thedetector 56. - The
excitation radiation source 54 can include any suitable source for emitting radiation at the desired wavelength, and can be capable of emitting a tunable wavelength of radiation. For example, commercially available semiconductor lasers, helium-neon lasers, carbon dioxide lasers, radiation-emitting diodes, incandescent lamps, and many other known radiation-emitting sources can be used as theexcitation radiation source 54. The wavelengths that are emitted by theexcitation radiation source 54 can include a suitable wavelength for performing NERS on the analyte. An exemplary range of wavelengths that can be emitted by theexcitation radiation source 54 includes wavelengths between about 350 nanometers and about 1000 nanometers. - The
detector 56 receives and detects the Raman scatteredradiation 66 generated by Raman scattered photons that are scattered by the analyte. Thedetector 56 includes a device for determining the wavelength of the Raman scatteredradiation 66 such as, for example, a monochromator, and a device for determining the intensity of the Raman scatteredradiation 66 such as, for example, a photomultiplier. Typically, the Raman scatteredradiation 66 is scattered in all directions relative to theanalyte stage 52. Thus, the position of thedetector 56 relative to theanalyte stage 52 is not particularly important. However, thedetector 56 can be positioned at, for example, an angle of 90° relative to the direction of theincident excitation radiation 64 to minimize the intensity of anyexcitation radiation 64 that is incident on thedetector 56. -
Optical components 60 positioned between thesource 54 and theanalyte stage 52 can be used to collimate, filter, or focus theexcitation radiation 64 before theexcitation radiation 54 impinges on theanalyte stage 52 and the NERS-active structure 10.Optical components 60 positioned between theanalyte stage 52 and thedetector 56 can be used to collimate, filter, or focus the Raman scatteredradiation 66. For example, a filter or a plurality of filters can be employed to prevent radiation at wavelengths corresponding to theexcitation radiation 64 from impinging on thedetector 56, thus allowing only the Raman scatteredradiation 66 to be received by thedetector 56. - To perform NERS using the
NERS system 50, an analyte can be provided adjacent the NERS-active structure 10, and particularly adjacent the metallicactive nanoparticles 16. The NERS-active structure 10 and the analyte are then irradiated withexcitation radiation 64 provided by thesource 54. Raman scatteredradiation 66 scattered by the analyte is detected by thedetector 56. The NERS-active structure 10 of theanalyte stage 52 may enhance the intensity of the Raman scattered radiation that is scattered by the analyte as described previously herein. - The wavelengths and corresponding intensity of the Raman scattered
radiation 66 can be determined and used to identify and provide information about the analyte. - The methods disclosed herein allow for the formation of NERS-active structures that include metallic active nanoparticles having well controlled size, spacing, and density. These structures allow for improved nano-enhanced Raman spectroscopy and can be employed as analyte substrates that can significantly enhance the intensity of Raman scattered radiation scattered by an analyte disposed adjacent thereto. The performance of nanoscale electronics, optoelectronics, molecular sensors, and other devices employing the Raman effect can be improved by using the NERS-active structures disclosed herein.
- Although the foregoing description contains many specifics, these are not to be construed as limiting the scope of the present invention, but merely as providing certain exemplary embodiments. Similarly, other embodiments of the invention can be devised which do not depart from the spirit or scope of the present invention. The scope of the invention is, therefore, indicated and limited only by the appended claims and their legal equivalents, rather than by the foregoing description. All additions, deletions, and modifications to the invention, as disclosed herein, which fall within the meaning and scope of the claims, are encompassed by the present invention.
Claims (50)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/090,352 US7292334B1 (en) | 2005-03-25 | 2005-03-25 | Binary arrays of nanoparticles for nano-enhanced Raman scattering molecular sensors |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/090,352 US7292334B1 (en) | 2005-03-25 | 2005-03-25 | Binary arrays of nanoparticles for nano-enhanced Raman scattering molecular sensors |
Publications (2)
Publication Number | Publication Date |
---|---|
US20070252979A1 true US20070252979A1 (en) | 2007-11-01 |
US7292334B1 US7292334B1 (en) | 2007-11-06 |
Family
ID=38647959
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/090,352 Active 2025-11-06 US7292334B1 (en) | 2005-03-25 | 2005-03-25 | Binary arrays of nanoparticles for nano-enhanced Raman scattering molecular sensors |
Country Status (1)
Country | Link |
---|---|
US (1) | US7292334B1 (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070153267A1 (en) * | 2005-12-19 | 2007-07-05 | Hong Wang | Arrays of Nano Structures for Surface-Enhanced Raman Scattering |
US20090097021A1 (en) * | 2005-10-25 | 2009-04-16 | Kyushu University, National University Corporation | Substrate and Substrate Assembly for Use in Raman Spectroscopic Analysis |
US20110212512A1 (en) * | 2005-12-19 | 2011-09-01 | Hong Wang | Monitoring network based on nano-structured sensing devices |
US20130107250A1 (en) * | 2011-10-27 | 2013-05-02 | Wei Wu | Free-standing structures for molecular analysis |
JP2014010154A (en) * | 2012-06-29 | 2014-01-20 | National Institute For Materials Science | Surface enhanced raman spectroscopic analysis(sers) substrate, method for manufacturing the same and biosensor using the same and micro channel device using the same |
JP2015052562A (en) * | 2013-09-09 | 2015-03-19 | 大日本印刷株式会社 | Substrate for measuring surface enhanced raman scattering, and method for manufacturing the sane |
CN104713869A (en) * | 2015-04-03 | 2015-06-17 | 重庆工商大学 | Application of hybridization perovskite meta-surface to Raman spectrum enhancement |
US20160003817A1 (en) * | 2012-04-10 | 2016-01-07 | The Trustees Of Princeton University | Rapid and sensitive analyte measurement assay |
WO2017184155A1 (en) * | 2016-04-21 | 2017-10-26 | Hewlett-Packard Development Company, L.P. | Sels nano finger sidewall coating layer |
US20210060604A1 (en) * | 2019-08-29 | 2021-03-04 | Purdue Research Foundation | Process and device for large-scale noncovalent functionalization of nanometer-scale 2d materials using heated roller langmuir-schaefer conversion |
RU2767946C2 (en) * | 2017-12-14 | 2022-03-22 | Сафтра Фотоникс, С.Р.О. | Nanooptical plasmon chip for detecting substances or molecules in the environment, food and biological systems |
CN115975239A (en) * | 2022-09-22 | 2023-04-18 | 江西科技师范大学 | Wrinkled nanometer bowl @ nanometer particle plasmon thin film and preparation method and application thereof |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20060255333A1 (en) * | 2005-05-12 | 2006-11-16 | Kuekes Philip J | Method of forming a controlled distribution of nano-particles on a surface |
US7403287B2 (en) * | 2005-06-08 | 2008-07-22 | Canon Kabushiki Kaisha | Sensing element used in sensing device for sensing target substance in specimen by using plasmon resonance |
US7514013B2 (en) * | 2005-09-12 | 2009-04-07 | Mark Logan | Devices with thermoelectric and thermodiodic characteristics and methods for manufacturing same |
US7632425B1 (en) * | 2006-10-06 | 2009-12-15 | General Electric Company | Composition and associated method |
US20080083299A1 (en) * | 2006-10-06 | 2008-04-10 | General Electric Company | Composition and associated method |
US20090214392A1 (en) * | 2008-02-27 | 2009-08-27 | The Texas A&M University System | Nano-fluidic Trapping Device for Surface-Enhanced Raman Spectroscopy |
TWI500921B (en) * | 2013-01-14 | 2015-09-21 | Ind Tech Res Inst | Optical sensing chip |
US9929213B2 (en) | 2016-01-27 | 2018-03-27 | Western Digital Technologies, Inc. | Nano-particle matrix for 3D NVM RRAM |
Citations (41)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4674878A (en) * | 1985-05-09 | 1987-06-23 | The United States Of America As Represented By The United States Department Of Energy | Practical substrate and apparatus for static and continuous monitoring by surface-enhanced raman spectroscopy |
US4944985A (en) * | 1988-04-11 | 1990-07-31 | Leach & Garner | Method for electroless plating of ultrafine or colloidal particles and products produced thereby |
US5017007A (en) * | 1989-07-27 | 1991-05-21 | Milne Christopher G | Apparatus and microbase for surface-enhanced raman spectroscopy system and method for producing same |
US5242828A (en) * | 1988-11-10 | 1993-09-07 | Pharmacia Biosensor Ab | Sensing surfaces capable of selective biomolecular interactions, to be used in biosensor systems |
US5255067A (en) * | 1990-11-30 | 1993-10-19 | Eic Laboratories, Inc. | Substrate and apparatus for surface enhanced Raman spectroscopy |
US5527712A (en) * | 1991-07-22 | 1996-06-18 | Medifor Limited, An Irish Corporation | Substrate and process for forming substrate for surface-enhanced analytical procedures |
US5609907A (en) * | 1995-02-09 | 1997-03-11 | The Penn State Research Foundation | Self-assembled metal colloid monolayers |
US5772905A (en) * | 1995-11-15 | 1998-06-30 | Regents Of The University Of Minnesota | Nanoimprint lithography |
US5837552A (en) * | 1991-07-22 | 1998-11-17 | Medifor, Ltd. | Surface-enhanced analytical procedures and substrates |
US5864397A (en) * | 1997-09-15 | 1999-01-26 | Lockheed Martin Energy Research Corporation | Surface-enhanced raman medical probes and system for disease diagnosis and drug testing |
US5885753A (en) * | 1996-04-12 | 1999-03-23 | The Texas A&M University System | Polymeric self-assembled mono- and multilayers and their use in photolithography |
US6025202A (en) * | 1995-02-09 | 2000-02-15 | The Penn State Research Foundation | Self-assembled metal colloid monolayers and detection methods therewith |
US6149868A (en) * | 1997-10-28 | 2000-11-21 | The Penn State Research Foundation | Surface enhanced raman scattering from metal nanoparticle-analyte-noble metal substrate sandwiches |
US6165911A (en) * | 1999-12-29 | 2000-12-26 | Calveley; Peter Braden | Method of patterning a metal layer |
US6242264B1 (en) * | 1996-09-04 | 2001-06-05 | The Penn State Research Foundation | Self-assembled metal colloid monolayers having size and density gradients |
US6248674B1 (en) * | 2000-02-02 | 2001-06-19 | Hewlett-Packard Company | Method of aligning nanowires |
US6365059B1 (en) * | 2000-04-28 | 2002-04-02 | Alexander Pechenik | Method for making a nano-stamp and for forming, with the stamp, nano-size elements on a substrate |
US6406777B1 (en) * | 2000-06-14 | 2002-06-18 | The United States Of America As Represented By The Secretary Of The Navy | Metal and glass structure for use in surface enhanced Raman spectroscopy and method for fabricating same |
US6432740B1 (en) * | 2001-06-28 | 2002-08-13 | Hewlett-Packard Company | Fabrication of molecular electronic circuit by imprinting |
US20020142480A1 (en) * | 2001-01-26 | 2002-10-03 | Surromed, Inc. | Surface-enhanced spectroscopy-active sandwich nanoparticles |
US20030059820A1 (en) * | 1997-11-26 | 2003-03-27 | Tuan Vo-Dinh | SERS diagnostic platforms, methods and systems microarrays, biosensors and biochips |
US6579721B1 (en) * | 1999-07-30 | 2003-06-17 | Surromed, Inc. | Biosensing using surface plasmon resonance |
US20030120137A1 (en) * | 2001-12-21 | 2003-06-26 | Romuald Pawluczyk | Raman spectroscopic system with integrating cavity |
US20030165418A1 (en) * | 2002-02-11 | 2003-09-04 | Rensselaer Polytechnic Institute | Directed assembly of highly-organized carbon nanotube architectures |
US20030174384A1 (en) * | 2001-10-24 | 2003-09-18 | Wm. Marsh Rice University | Nanoparticle-based all-optical sensors |
US6623977B1 (en) * | 1999-11-05 | 2003-09-23 | Real-Time Analyzers, Inc. | Material for surface-enhanced Raman spectroscopy, and SER sensors and method for preparing same |
US6649683B2 (en) * | 1999-04-06 | 2003-11-18 | Avalon Instruments Limited | Solid matrices for surface-enhanced raman spectroscopy |
US20030231304A1 (en) * | 2002-06-12 | 2003-12-18 | Selena Chan | Metal coated nanocrystalline silicon as an active surface enhanced raman spectroscopy (SERS) substrate |
US20040077844A1 (en) * | 2002-07-17 | 2004-04-22 | Jacobson Joseph M. | Nanoparticle chains and preparation thereof |
US20040135997A1 (en) * | 2002-06-12 | 2004-07-15 | Selena Chan | Metal coated nanocrystalline silicon as an active surface enhanced raman spectroscopy (SERS) substrate |
US20040134778A1 (en) * | 2001-04-17 | 2004-07-15 | Martin Stelzle | Pair of measuring electrodes, biosensor comprising a pair of measuring electrodes of this type, and production process |
US20040150818A1 (en) * | 1999-05-17 | 2004-08-05 | Armstrong Robert L. | Optical devices and methods employing nanoparticles, microcavities, and semicontinuous metal films |
US6773616B1 (en) * | 2001-11-13 | 2004-08-10 | Hewlett-Packard Development Company, L.P. | Formation of nanoscale wires |
US6781690B2 (en) * | 1999-05-17 | 2004-08-24 | New Mexico State University Technology Transfer Corporation | Sensors employing nanoparticles and microcavities |
US20050142567A1 (en) * | 2003-12-29 | 2005-06-30 | Intel Corporation | Composite organic-inorganic nanoparticles and methods for use thereof |
US20060017918A1 (en) * | 2004-07-23 | 2006-01-26 | Cullum Brian M | Multilayered surface-enhanced Raman scattering substrates |
US20060054881A1 (en) * | 2004-09-16 | 2006-03-16 | Zhiyong Li | SERS-active structures including nanowires |
US7057732B2 (en) * | 1999-01-25 | 2006-06-06 | Amnis Corporation | Imaging platform for nanoparticle detection applied to SPR biomolecular interaction analysis |
US20060164634A1 (en) * | 2005-01-27 | 2006-07-27 | Kamins Theodore I | Nano-enhanced Raman spectroscopy-active nanostructures including elongated components and methods of making the same |
US20060209300A1 (en) * | 2005-03-17 | 2006-09-21 | Kamins Theodore I | Ordered array of nanoparticles for efficient nanoenhanced Raman scattering detection and methods of forming the same |
US7212284B2 (en) * | 2004-05-12 | 2007-05-01 | General Electric Company | Method for forming nanoparticle films and application thereof |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE60334029D1 (en) | 2002-11-26 | 2010-10-14 | Univ Maryland Biotechnology | HIGHLY SENSITIVE ASSAYS FOR PATHOGENIC DETECTION USING METAL-REINFORCED FLUORESCENCE |
-
2005
- 2005-03-25 US US11/090,352 patent/US7292334B1/en active Active
Patent Citations (43)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4674878A (en) * | 1985-05-09 | 1987-06-23 | The United States Of America As Represented By The United States Department Of Energy | Practical substrate and apparatus for static and continuous monitoring by surface-enhanced raman spectroscopy |
US4944985A (en) * | 1988-04-11 | 1990-07-31 | Leach & Garner | Method for electroless plating of ultrafine or colloidal particles and products produced thereby |
US5242828A (en) * | 1988-11-10 | 1993-09-07 | Pharmacia Biosensor Ab | Sensing surfaces capable of selective biomolecular interactions, to be used in biosensor systems |
US5017007A (en) * | 1989-07-27 | 1991-05-21 | Milne Christopher G | Apparatus and microbase for surface-enhanced raman spectroscopy system and method for producing same |
US5255067A (en) * | 1990-11-30 | 1993-10-19 | Eic Laboratories, Inc. | Substrate and apparatus for surface enhanced Raman spectroscopy |
US5837552A (en) * | 1991-07-22 | 1998-11-17 | Medifor, Ltd. | Surface-enhanced analytical procedures and substrates |
US5527712A (en) * | 1991-07-22 | 1996-06-18 | Medifor Limited, An Irish Corporation | Substrate and process for forming substrate for surface-enhanced analytical procedures |
US5609907A (en) * | 1995-02-09 | 1997-03-11 | The Penn State Research Foundation | Self-assembled metal colloid monolayers |
US6025202A (en) * | 1995-02-09 | 2000-02-15 | The Penn State Research Foundation | Self-assembled metal colloid monolayers and detection methods therewith |
US5772905A (en) * | 1995-11-15 | 1998-06-30 | Regents Of The University Of Minnesota | Nanoimprint lithography |
US5885753A (en) * | 1996-04-12 | 1999-03-23 | The Texas A&M University System | Polymeric self-assembled mono- and multilayers and their use in photolithography |
US20030157732A1 (en) * | 1996-09-04 | 2003-08-21 | Baker Bonnie E. | Self-assembled metal colloid monolayers |
US6242264B1 (en) * | 1996-09-04 | 2001-06-05 | The Penn State Research Foundation | Self-assembled metal colloid monolayers having size and density gradients |
US5864397A (en) * | 1997-09-15 | 1999-01-26 | Lockheed Martin Energy Research Corporation | Surface-enhanced raman medical probes and system for disease diagnosis and drug testing |
US6149868A (en) * | 1997-10-28 | 2000-11-21 | The Penn State Research Foundation | Surface enhanced raman scattering from metal nanoparticle-analyte-noble metal substrate sandwiches |
US20030059820A1 (en) * | 1997-11-26 | 2003-03-27 | Tuan Vo-Dinh | SERS diagnostic platforms, methods and systems microarrays, biosensors and biochips |
US7057732B2 (en) * | 1999-01-25 | 2006-06-06 | Amnis Corporation | Imaging platform for nanoparticle detection applied to SPR biomolecular interaction analysis |
US6649683B2 (en) * | 1999-04-06 | 2003-11-18 | Avalon Instruments Limited | Solid matrices for surface-enhanced raman spectroscopy |
US6781690B2 (en) * | 1999-05-17 | 2004-08-24 | New Mexico State University Technology Transfer Corporation | Sensors employing nanoparticles and microcavities |
US20040150818A1 (en) * | 1999-05-17 | 2004-08-05 | Armstrong Robert L. | Optical devices and methods employing nanoparticles, microcavities, and semicontinuous metal films |
US6579721B1 (en) * | 1999-07-30 | 2003-06-17 | Surromed, Inc. | Biosensing using surface plasmon resonance |
US6623977B1 (en) * | 1999-11-05 | 2003-09-23 | Real-Time Analyzers, Inc. | Material for surface-enhanced Raman spectroscopy, and SER sensors and method for preparing same |
US6165911A (en) * | 1999-12-29 | 2000-12-26 | Calveley; Peter Braden | Method of patterning a metal layer |
US6248674B1 (en) * | 2000-02-02 | 2001-06-19 | Hewlett-Packard Company | Method of aligning nanowires |
US6365059B1 (en) * | 2000-04-28 | 2002-04-02 | Alexander Pechenik | Method for making a nano-stamp and for forming, with the stamp, nano-size elements on a substrate |
US6406777B1 (en) * | 2000-06-14 | 2002-06-18 | The United States Of America As Represented By The Secretary Of The Navy | Metal and glass structure for use in surface enhanced Raman spectroscopy and method for fabricating same |
US20020142480A1 (en) * | 2001-01-26 | 2002-10-03 | Surromed, Inc. | Surface-enhanced spectroscopy-active sandwich nanoparticles |
US20040134778A1 (en) * | 2001-04-17 | 2004-07-15 | Martin Stelzle | Pair of measuring electrodes, biosensor comprising a pair of measuring electrodes of this type, and production process |
US6432740B1 (en) * | 2001-06-28 | 2002-08-13 | Hewlett-Packard Company | Fabrication of molecular electronic circuit by imprinting |
US20030174384A1 (en) * | 2001-10-24 | 2003-09-18 | Wm. Marsh Rice University | Nanoparticle-based all-optical sensors |
US6778316B2 (en) * | 2001-10-24 | 2004-08-17 | William Marsh Rice University | Nanoparticle-based all-optical sensors |
US6773616B1 (en) * | 2001-11-13 | 2004-08-10 | Hewlett-Packard Development Company, L.P. | Formation of nanoscale wires |
US20030120137A1 (en) * | 2001-12-21 | 2003-06-26 | Romuald Pawluczyk | Raman spectroscopic system with integrating cavity |
US20030165418A1 (en) * | 2002-02-11 | 2003-09-04 | Rensselaer Polytechnic Institute | Directed assembly of highly-organized carbon nanotube architectures |
US20040135997A1 (en) * | 2002-06-12 | 2004-07-15 | Selena Chan | Metal coated nanocrystalline silicon as an active surface enhanced raman spectroscopy (SERS) substrate |
US20030231304A1 (en) * | 2002-06-12 | 2003-12-18 | Selena Chan | Metal coated nanocrystalline silicon as an active surface enhanced raman spectroscopy (SERS) substrate |
US20040077844A1 (en) * | 2002-07-17 | 2004-04-22 | Jacobson Joseph M. | Nanoparticle chains and preparation thereof |
US20050142567A1 (en) * | 2003-12-29 | 2005-06-30 | Intel Corporation | Composite organic-inorganic nanoparticles and methods for use thereof |
US7212284B2 (en) * | 2004-05-12 | 2007-05-01 | General Electric Company | Method for forming nanoparticle films and application thereof |
US20060017918A1 (en) * | 2004-07-23 | 2006-01-26 | Cullum Brian M | Multilayered surface-enhanced Raman scattering substrates |
US20060054881A1 (en) * | 2004-09-16 | 2006-03-16 | Zhiyong Li | SERS-active structures including nanowires |
US20060164634A1 (en) * | 2005-01-27 | 2006-07-27 | Kamins Theodore I | Nano-enhanced Raman spectroscopy-active nanostructures including elongated components and methods of making the same |
US20060209300A1 (en) * | 2005-03-17 | 2006-09-21 | Kamins Theodore I | Ordered array of nanoparticles for efficient nanoenhanced Raman scattering detection and methods of forming the same |
Cited By (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090097021A1 (en) * | 2005-10-25 | 2009-04-16 | Kyushu University, National University Corporation | Substrate and Substrate Assembly for Use in Raman Spectroscopic Analysis |
US8582099B2 (en) | 2005-12-19 | 2013-11-12 | Optotrace Technologies, Inc. | Monitoring network based on nano-structured sensing devices |
US7460224B2 (en) * | 2005-12-19 | 2008-12-02 | Opto Trace Technologies, Inc. | Arrays of nano structures for surface-enhanced Raman scattering |
US20090066946A1 (en) * | 2005-12-19 | 2009-03-12 | Hong Wang | Arrays of nano structures for surface-enhanced raman scattering |
US7576854B2 (en) * | 2005-12-19 | 2009-08-18 | Optotrace Technologies, Inc. | Arrays of nano structures for surface-enhanced raman scattering |
US20100110424A1 (en) * | 2005-12-19 | 2010-05-06 | Hong Wang | Nano structured sensing device for surface-enhanced raman scattering |
US7929133B2 (en) | 2005-12-19 | 2011-04-19 | Opto Trace Technologies, Inc. | Nano structured sensing device for surface-enhanced Raman scattering |
US20110212512A1 (en) * | 2005-12-19 | 2011-09-01 | Hong Wang | Monitoring network based on nano-structured sensing devices |
US20070153267A1 (en) * | 2005-12-19 | 2007-07-05 | Hong Wang | Arrays of Nano Structures for Surface-Enhanced Raman Scattering |
US20130107250A1 (en) * | 2011-10-27 | 2013-05-02 | Wei Wu | Free-standing structures for molecular analysis |
US20160003817A1 (en) * | 2012-04-10 | 2016-01-07 | The Trustees Of Princeton University | Rapid and sensitive analyte measurement assay |
JP2014010154A (en) * | 2012-06-29 | 2014-01-20 | National Institute For Materials Science | Surface enhanced raman spectroscopic analysis(sers) substrate, method for manufacturing the same and biosensor using the same and micro channel device using the same |
JP2015052562A (en) * | 2013-09-09 | 2015-03-19 | 大日本印刷株式会社 | Substrate for measuring surface enhanced raman scattering, and method for manufacturing the sane |
CN104713869A (en) * | 2015-04-03 | 2015-06-17 | 重庆工商大学 | Application of hybridization perovskite meta-surface to Raman spectrum enhancement |
WO2017184155A1 (en) * | 2016-04-21 | 2017-10-26 | Hewlett-Packard Development Company, L.P. | Sels nano finger sidewall coating layer |
US11320379B2 (en) | 2016-04-21 | 2022-05-03 | Hewlett-Packard Development Company, L.P. | SELS nano finger sidewall coating layer |
RU2767946C2 (en) * | 2017-12-14 | 2022-03-22 | Сафтра Фотоникс, С.Р.О. | Nanooptical plasmon chip for detecting substances or molecules in the environment, food and biological systems |
US20210060604A1 (en) * | 2019-08-29 | 2021-03-04 | Purdue Research Foundation | Process and device for large-scale noncovalent functionalization of nanometer-scale 2d materials using heated roller langmuir-schaefer conversion |
CN115975239A (en) * | 2022-09-22 | 2023-04-18 | 江西科技师范大学 | Wrinkled nanometer bowl @ nanometer particle plasmon thin film and preparation method and application thereof |
Also Published As
Publication number | Publication date |
---|---|
US7292334B1 (en) | 2007-11-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7292334B1 (en) | Binary arrays of nanoparticles for nano-enhanced Raman scattering molecular sensors | |
US7245370B2 (en) | Nanowires for surface-enhanced Raman scattering molecular sensors | |
US7397558B2 (en) | Ordered array of nanoparticles for efficient nanoenhanced Raman scattering detection and methods of forming the same | |
US7426025B2 (en) | Nanostructures, systems, and methods including nanolasers for enhanced Raman spectroscopy | |
US9176065B2 (en) | Nanoscale array structures suitable for surface enhanced raman scattering and methods related thereto | |
US7158219B2 (en) | SERS-active structures including nanowires | |
US7236242B2 (en) | Nano-enhanced Raman spectroscopy-active nanostructures including elongated components and methods of making the same | |
US8559003B2 (en) | Electrically driven devices for surface enhanced raman spectroscopy | |
US7388661B2 (en) | Nanoscale structures, systems, and methods for use in nano-enhanced raman spectroscopy (NERS) | |
US8993339B2 (en) | Hybrid nanostructures for molecular analysis | |
US20130040862A1 (en) | Multi-pillar structure for molecular analysis | |
US20110166045A1 (en) | Wafer scale plasmonics-active metallic nanostructures and methods of fabricating same | |
US7391511B1 (en) | Raman signal-enhancing structures and Raman spectroscopy systems including such structures | |
Kawasaki et al. | Core–shell-structured gold nanocone array for label-free DNA sensing | |
EP2459988A1 (en) | Nanowire light concentrators for performing raman spectroscopy | |
US8848183B2 (en) | Apparatus having nano-fingers of different physical characteristics | |
US7321422B2 (en) | SERS-active structures having nanoscale dimensions | |
JP2008512668A (en) | Raman spectroscopy | |
US20130107250A1 (en) | Free-standing structures for molecular analysis | |
Hao et al. | Flexible surface-enhanced Raman scattering chip: A universal platform for real-time interfacial molecular analysis with femtomolar sensitivity | |
US7474397B2 (en) | Raman and hyper-Raman excitation using superlensing | |
US20130196449A1 (en) | Electrically driven devices for surface enhanced raman spectroscopy | |
Tsargorodska et al. | Fast, simple, combinatorial routes to the fabrication of reusable, plasmonically active gold nanostructures by interferometric lithography of self-assembled monolayers | |
US7309642B2 (en) | Metallic quantum dots fabricated by a superlattice structure | |
Rigó et al. | Enhancement in inverse pyramid SERS substrates with entrapped gold nanoparticles |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P., TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BRATKOVSKI, ALEXANDRE M.;KAMINS, THEODORE I.;REEL/FRAME:016424/0454;SIGNING DATES FROM 20050321 TO 20050323 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
REMI | Maintenance fee reminder mailed | ||
FPAY | Fee payment |
Year of fee payment: 8 |
|
SULP | Surcharge for late payment |
Year of fee payment: 7 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 12TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1553); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 12 |