CN110499155A - A kind of nitrogen-doped graphene quantum dot and its preparation method and application - Google Patents
A kind of nitrogen-doped graphene quantum dot and its preparation method and application Download PDFInfo
- Publication number
- CN110499155A CN110499155A CN201910700815.3A CN201910700815A CN110499155A CN 110499155 A CN110499155 A CN 110499155A CN 201910700815 A CN201910700815 A CN 201910700815A CN 110499155 A CN110499155 A CN 110499155A
- Authority
- CN
- China
- Prior art keywords
- nitrogen
- quantum dot
- graphene quantum
- doped graphene
- fluorescence
- 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.)
- Pending
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
- C09K11/65—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing carbon
-
- 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
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/6428—Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes"
-
- 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
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/6428—Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes"
- G01N2021/6432—Quenching
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Nanotechnology (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Materials Engineering (AREA)
- Immunology (AREA)
- Optics & Photonics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Pathology (AREA)
- General Health & Medical Sciences (AREA)
- Biophysics (AREA)
- Biochemistry (AREA)
- Analytical Chemistry (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Composite Materials (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Organic Chemistry (AREA)
- Luminescent Compositions (AREA)
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
Abstract
The invention discloses the applications of a kind of nitrogen-doped graphene quantum dot and preparation method thereof and detection mercury ion and cysteine, belong to fluorescence sense technical field.The preparation method includes that carbon-source cpd and nitrogen source compound are dissolved in water to obtain mixed aqueous solution, the nitrogen-doped graphene quantum dot is made in hydro-thermal reaction under alkaline condition, the carbon-source cpd is 1,3,6- trinitro- pyrene, nitrogen source compound is tryptophan, and alkaline condition is adjusted by sodium hydroxide.The preparation method yield is high, can once realize that gram-grade synthesizes.Due to the doping of high content nitrogen atom, so that nitrogen-doped graphene quantum dot obtained is with blue-fluorescence and has unique mercury ion selectivity.Based on mercury ion to the quenching of nitrogen-doped graphene quantum dot fluorescence, it can be achieved that the Smart fluorescent to mercury ion detects, detection limit is low.Since cysteine can restore the fluorescence quenched by mercury ion, nitrogen-doped graphene quantum dot combination mercury ion can realize the fluorescence detection to cysteine.
Description
Technical field
The present invention relates to fluorescence sense technical fields, and in particular to a kind of nitrogen-doped graphene quantum dot and preparation method thereof
With the application in fluorescence detection mercury ion and cysteine.
Background technique
Small molecule plays a crucial role in various physiology and pathologic process.For example, mercury ion (Hg2+) it is a kind of
Most toxic pollutant has very big threat to environment and human health, it can be methylated by microorganism and is converted into
Then more toxic methyl mercury is accumulated in vivo by food chain.Even low concentration takes in Hg2+Also can damage nerve,
Endocrine and other systems, and then lead to many fatal diseases, such as headache, kidney failure, mental loss.Cysteine is as people
One of body essential amino acid, nerve fiber, metabolism and in terms of have important physiological function, the exception of cysteine
Level can lead to growth retardation, neurotoxicity effect, Alzheimer disease and coronary heart disease.Therefore, to Hg2+It is carried out with cysteine
Simply, sensitively detection is of great significance.
Fluorescence analysis is widely noticed due to having many advantages, such as easy to operate quick, at low cost.The core of fluorescence sense is
The nontoxic Fluorescence Fluorescence probe that luminous intensity is high, selectivity is strong.Graphene quantum dot (GQDs) be nano-sized carbon family it is newest at
Member, has photoluminescent property due to uniform significant quantum confined effect.Due to, good biocompatibility adjustable with band gap, light
The advantages that stability is high, GQDs present wide application prospect in fields such as fluorescence sense, bio-imagings.GQDs can pass through
Coordination, electrostatic interaction occur the modes such as electronics transfer and heavy metal ion effect and lead to fluorescent quenching.Based on this principle,
The fluorescence sense system of building fluorescent quenching (turn-off) mode can be used for the fluorescence detection of heavy metal ion.In addition to this,
Specific small molecule and metal ion have strong interaction, this effect can destroy the effect of GQDs and metal ion, cause
The fluorescence of GQDs restores.Based on this principle, the fluorescence sense mode realization that fluorescent quenching restores (turn-off-on) can be constructed
Detection.
Recent studies indicate that Heteroatom doping can effectively adjust the property of GQDs.Such as patent document CN
106800294 A disclose a kind of graphene quantum dot of thymidine modification, when preparation, carbon fiber are dissolved in strong acid, is added
Heat reflux, obtains reflux solution A, and mixing with water and adjusting pH is 7-9, obtains graphene quantum dot solution；After activated, second two is added
Amine, which reacts, is made the covalent modification graphene quantum dot solution of ethylenediamine；Thymidine -1- acetic acid after activation is added, reaction
The graphene quantum dot of thymidine modification is made.Graphene quantum dot is by connecting ethylenediamine using amido bond and thymus gland is phonetic
Pyridine -1- acetic acid achievees the purpose that specific detection mercury ion, and mechanism is N atom and mercury ion spy on thymidine 3
The opposite sex combines, and causes the aggregation of graphene quantum dot, to make the fluorescent quenching of graphene quantum dot.
However, simplicity and the gram-grade synthesis of the doping type GQDs with special metal ion selectivity still faces the challenge.Mesh
Before there is no high yield, the gram-grade preparation method of the doping type GQDs with mercury ion selectivity.
Summary of the invention
The purpose of the present invention is to provide the doping type graphene quantums that a kind of pair of mercury ion has Selective recognition ability
Point, and the preparation method of easy gram-grade synthesis is provided.
To achieve the above object, the present invention adopts the following technical scheme:
A kind of preparation method of nitrogen-doped graphene quantum dot, comprising: carbon-source cpd and nitrogen source compound are dissolved in water
In obtain mixed aqueous solution, the nitrogen-doped graphene quantum dot, the carbon source is made in hydro-thermal reaction under alkaline condition
Conjunction object is 1,3,6- trinitro- pyrenes, and nitrogen source compound is tryptophan.
For the present invention using 1,3,6- trinitro- pyrenes as carbon source, which has the mother nucleus structure of similar graphene, has
The graphene quantum dot with advantageous crystalline is prepared conducive in such a way that molecule from bottom to top merges.In addition, nitro
With strong electrophilicity, addition reaction can occur with the group of electron rich, be conducive to prepare Heteroatom doping or functional group connects
The functional graphene quantum dot of branch.Amino, N atom in tryptophan (D-trp, L-Trp, DL-tryptophan) molecule,
Hydroxide ion in carboxyl and alkaline solution has additivity, and the nitro site on pyrene ring can be added in hydro-thermal reaction,
Realize the synthesis of nitrogen atom doping type graphene quantum dot.
The reaction product that above-mentioned technical proposal is prepared is through x-ray photoelectron spectroscopy figure score, C1s High Resolution Spectrum, O1s
High Resolution Spectrum, N1s High Resolution Spectrum characterization confirm in the atom doped lattice to GQDs of N, this demonstrate that nitrogen-doped graphene amount
Son point is effectively synthesized.
Studies have shown that reaction product has strong blue-fluorescence under the ultraviolet light irradiation of 365nm.However, 1,3,6- tri-
Nitropyrene and sodium hydroxide mixed solution issue that penetrate green glimmering through same hydro-thermal reaction acquired solution in the ultraviolet light irradiation of 365nm
Light.Tryptophan and sodium hydroxide mixed solution through same hydro-thermal reaction acquired solution the ultraviolet light irradiation of 365nm issue penetrate it is weak
Green fluorescence.This valid certificates prepares nitrogen-doped graphene quantum dot to quantum-dot structure, energy using tryptophan as nitrogen source
The regulation of grade, luminescent properties.
The medium of hydro-thermal reaction is 1,3,6- trinitro- pyrene and the mixing containing tryptophan and hydroxide ion in the present invention
Solution.When 1,3,6- trinitro- pyrene excessive concentration of carbon source, it is easy to get to oversized graphene quantum dot and reduces its fluorescence
Performance, therefore, the concentration of 1,3,6- trinitro- pyrene are unsuitable excessively high.Preferably, 1,3,6- trinitro- in the mixed aqueous solution
The concentration of pyrene is 0.2~8mmol/L, and the concentration of tryptophan is 5~75mmol/L.
Alkaline condition is adjusted by sodium hydroxide, and the concentration of sodium hydroxide is 15~300mmol/L in reaction system.Due to alkali
Property condition be conducive to trinitro- pyrene molecule fusion, and tryptophan have certain acidity, for be conducive to reaction system maintain compared with
High alkalinity, sodium hydroxide and Tryptophan concentration ratio are 3:1~25:1.
More preferably, the concentration of 1,3,6- trinitro- pyrenes is 3~6mmol/L in reaction system, the concentration of tryptophan is 15
~20mmol/L, the concentration of sodium hydroxide are 100~200mmol/L.
High temperature can promote the reaction efficiency merged from bottom to top.Reaction time is too short, and molecule fusion is incomplete, the amount of causing
Son point concentration is lower, and overlong time, then may cause quantum dot accumulation influences product property.Comprehensive water heating kettle tolerable temperature,
Preferably, the temperature of the hydro-thermal reaction is 140~200 DEG C, the time is 4~12 hours.
To remove unreacted small molecule, and the consistent nitrogen-doped graphene quantum dot of luminosity is obtained, needed to anti-
Product is answered to carry out removal of impurities and size classification.Mixed aqueous solution obtains reaction product after hydro-thermal reaction, retains in reaction product and divides
Nitrogen-doped graphene quantum dot of the son amount between 1000~3500Da is nitrogen-doped graphene quantum dot of the invention.
Preferably, being mixed using the nitrogen of dialysis or ultrafiltration retention reaction product middle-molecular-weihydroxyethyl between 1000~3500Da
Miscellaneous graphene quantum dot.
Specifically, product dialysis method of purification are as follows: reaction product is sufficiently saturating through the bag filter that molecular cut off is 1000Da
It is after analysis removes unreacted small molecule, solution in bag filter is sufficiently saturating for the bag filter of 3500Da through molecular cut off again
Analysis, the outer solution of bag filter is nitrogen-doped graphene quantum dot solution.It is dialysed twice and carries out the N doping graphite of size retention
Alkene quantum dot is free from foreign meter, and has uniform structure.
Product Ultrafiltration Purifying method are as follows: reaction product is centrifuged under 8000 turns through the super filter tube that molecular cut off is 1000Da
30 minutes, after removing unreacted small molecule, the super filter tube for being again 3500Da through molecular cut off by super filter tube top solution
It is centrifuged 30 minutes under 7000 turns, super filter tube lower part solution is nitrogen-doped graphene quantum dot solution.
Nitrogen-doped graphene quantum dot preparation method yield provided by the invention is high, is greater than with the yield that carbon source calculates
90%.This is attributed to carbon-source cpd and the effective integration of doping nitrogen source under alkaline condition, and product structure and size uniformity,
The impurity such as the carbon nano-particles that coexist, the small molecule not merged are few.Use volume that can synthesize gram for the water heating kettle single batch of 1L
Grade graphene quantum dot.
The present invention also provides the nitrogen-doped graphene quantum dots as made from above-mentioned preparation method.Preparation method of the present invention is closed
At nitrogen-doped graphene quantum dot to have of uniform size, average-size be about 2.1nm, the high (high-resolution-ration transmission electric-lens of crystallinity
Photo is clear that lattice), the good structure feature such as single-layer graphene thickness degree.
Nitrogen-doped graphene quantum dot prepared by the present invention emits blue-fluorescence under 365nm ultraviolet light, and maximum swashs
Hair wavelength is 370nm, maximum emission wavelength 445nm.Due to the doping of high content nitrogen atom, so that N doping graphite obtained
Alkene quantum dot has high absolute quantum yield (being higher than 20%), and works as and excite N doping graphite with 340-410nm excitation wavelength
When alkene quantum dot, fluorescent emission peak position does not change.In addition, the gained nitrogen-doped graphene quantum under maximum excitation wavelength
The fluorescence peak half-peak breadth of point is about 55nm, it was demonstrated that its structure is uniform.
Compared with carbon atom, N atom is with strong electronegativity and has lone pair electrons, can be coordinated with metal ion
Effect or electron transfer reaction.In addition, nitrogen atom doping graphene quantum dot also has amino, carboxyl structure, these groups
In conjunction with the nitrogen-atoms of doping special metalloform-selective can be generated by synergistic effect.
The present invention also provides application of the nitrogen-doped graphene quantum dot of above method preparation in detection mercury ion.
Nitrogen-doped graphene quantum dot prepared by the present invention generates blue-fluorescence, fluorescence under the excitation of 365nm ultraviolet lamp
It can be quenched by mercury ion conspicuousness, including sodium ion, potassium ion, calcium ion, magnesium ion, zinc ion, aluminium ion, nickel ion, cobalt
Other metal ions including ion, chromium ion, lead ion, cadmium ion and silver ion all cannot significantly quench its fluorescence.This card
Bright nitrogen-doped graphene quantum dot of the invention has Selective recognition ability and strong active force to mercury ion.
Hg has been investigated by fluorescence lifetime and dynamic light scattering2+Quench the mechanism of nitrogen-doped graphene quantum dot fluorescence.Knot
Fruit shows that nitrogen-doped graphene quantum dot is substantially reduced with the fluorescence lifetime after mercury ion effect, illustrates nitrogen-doped graphene amount
Electronics transfer has occurred between son point and mercury ion, leads to the fluorescent quenching of nitrogen-doped graphene quantum dot.This is attributed to nitrogen and mixes
N atom positions abundant on miscellaneous graphene quantum dot, these sites are Hg as strong electronegativity substance2+Provide electronics.In addition,
Dynamic light scattering after nitrogen-doped graphene quantum dot and mercury ion effect shows that the particle diameter in mixture increases to 1
μm or more, this is much larger than the average grain diameter of nitrogen-doped graphene quantum dot.Since nitrogen-doped graphene quantum dot has doping
Nitrogen-atoms, amino and carboxyl, these groups synergistic effect and Hg2+Between occur coordination lead to nitrogen-doped graphene quantum dot
Reunion so that cause fluorescence significantly to quench.
Dimercurion (Hg2+) it is one of most common mercury pollution form, it can be methylated by microorganism and is converted into
Then more toxic methyl mercury is accumulated in vivo by food chain.Hg2+The even Hg of low concentration2+Skin will be passed through
Skin, respiratory tract and stomach intestinal tissue lead to DNA, mitosis damage and central nervous system permanent damage.At present for mercury
The detection method of ion is mainly atomic absorption spectrophotometry, atomic fluorescence method, inductively coupled plasma mass spectrometry, cold original
Sub- absorption process etc..Equipment needed for these detection methods and its valuableness, and need the operator of Special Training.And fluorescence analysis
The content that mercury ion in sample is analyzed by the fluorescence intensity of fluorescence probe in detection solution, detects quick, high sensitivity, institute
Need sample size few.Nitrogen-doped graphene quantum dot prepared by the present invention reaches 19nmol/L for the minimum detection limit of mercury ion.
Studies have shown that in nitrogen-doped graphene quantum dot-Hg2+After cysteine is added in mixture, by Hg2+Quenching
The fluorescence of nitrogen-doped graphene quantum dot can restore.This is attributed to Hg2+With the strong combination on cysteine between thiol group
Ability destroys Hg2+Interaction between nitrogen-doped graphene quantum dot, leads to Hg2+From nitrogen-doped graphene quantum dot
Surface separation, so that the fluorescence of nitrogen-doped graphene quantum dot restores.
When in nitrogen-doped graphene quantum dot-Hg2+Histidine, methionine, tryptophan, tyrosine, bright is added in mixture
Propylhomoserin, threonine, alanine, glutamic acid or glycine can not restore the fluorescence of nitrogen-doped graphene quantum dot.Control experiment
Show that cysteine does not influence the fluorescence intensity of nitrogen-doped graphene quantum dot itself.This is strong to demonstrate half Guang ammonia
Acid makes it possible to recovery by Hg to the specific effect of mercury ion2+The fluorescence of the nitrogen-doped graphene quantum dot of quenching.It is based on
Cysteine can restore by Hg2+The phenomenon that fluorescence of the nitrogen-doped graphene quantum dot of quenching, it is extensive fluorescent quenching-can be constructed
The fluorescent optical sensor of complex pattern reaches 29nmol/L to the minimum detection limit of cysteine.
Therefore, prepared by the mixture acted on the present invention also provides the nitrogen-doped graphene quantum dot with mercury ion
Detect the application in cysteine kit.
Compared with prior art, the present invention have the utility model has the advantages that
(1) the method yield provided by the invention for preparing nitrogen-doped graphene quantum dot is high, and single batch synthesis can be realized
Gram-grade preparation.
(2) nitrogen-doped graphene quantum dot prepared by the present invention has strong blue-fluorescence, and absolute quantum yield is high, and glimmering
Light has excitation wavelength not dependent, when exciting nitrogen-doped graphene quantum dot with 340-410nm excitation wavelength, fluorescent emission
Peak position does not change.In addition, the fluorescence peak half-peak breadth of nitrogen-doped graphene quantum dot obtained by under maximum excitation wavelength is about
For 55nm.
(3) fluorescence of nitrogen-doped graphene quantum dot of the invention is quenched in which can dramatically by mercury ion, show its to mercury from
Son has apparent Selective recognition ability, is expected to be used for the selective enumeration method of trace amount mercury ion.
(4) fluorescence of nitrogen-doped graphene quantum dot of the invention is quenched in which can dramatically by mercury ion, but cysteine can
To restore the fluorescence being quenched, it is expected to be used for the selective enumeration method of trace cysteine.
Detailed description of the invention
Fig. 1 is that 1,3,6- trinitro- pyrene and the resulting product of sodium hydroxide mixed solution hydrothermal synthesis exist in comparative example 1
Photo under 365nm ultraviolet light.
Fig. 2 is the photograph of tryptophan, the resulting product of sodium hydroxide mixed solution hydrothermal synthesis at 365nm in comparative example 2
Piece.
Fig. 3 is photo of the nitrogen-doped graphene quantum dot solution of the preparation of embodiment 1 under 365nm ultraviolet light.
Fig. 4 is photograph when mercury ion (5 μm of ol/L) is added in nitrogen-doped graphene quantum dot under 365nm ultraviolet light
Piece.
Fig. 5 is fluorescent quenching rate when different metal ions (25 μm of ol/L) is added in nitrogen-doped graphene quantum dot.
Fig. 6 is the x-ray photoelectron spectroscopy figure score (A) of nitrogen-doped graphene quantum dot, C1s High Resolution Spectrum (B), O1s
High Resolution Spectrum (C), N1s High Resolution Spectrum (D).
Fig. 7 is the atomic force microscopy of nitrogen-doped graphene quantum dot.Interior illustration is its height distribution map.
Fig. 8 is the transmission electron microscope photo of nitrogen-doped graphene quantum dot.(A) icon ruler is 20nm, and (B) icon ruler is 5nm.
Fig. 9 be nitrogen-doped graphene quantum dot excitation spectrum and 340nm to 410nm excitation wavelength under obtained transmitting light
It composes (successively increasing 10nm by the excitation wavelength of adjacent curve from bottom to top).
Figure 10 is fluorescence spectra when various concentration mercury ion being added in nitrogen-doped graphene quantum dot.It is top-down
Ion concentration of mercury is respectively 0,50nmol/L, 100nmol/L, 300nmol/L, 500nmol/L, 1 μm of ol/L, 3 μm of ol/L, 5 μ
mol/L,7μmol/L,10μmol/L,12μmol/L,15μmol/L,20μmol/L,25μmol/L。
Figure 11 is the partial size that dynamic light scattering measures when mercury ion (25 μm of ol/L) being added in nitrogen-doped graphene quantum dot
Distribution map.
Figure 12 is fluorescence when various concentration cysteine being added in nitrogen-doped graphene quantum dot-mercury ion mixed solution
Spectrogram.Semicystinol concentration from bottom to top is respectively 0,100nmol/L, 300nmol/L, 500nmol/L, 1 μm of ol/L, 3 μ
mol/L,5μmol/L,7μmol/L,9μmol/L,10μmol/L,12μmol/L,15μmol/L,17μmol/L,20μmol/L,25
μmol/L,30μmol/L,40μmol/L,50μmol/L。
Specific embodiment
The invention will be further described with attached drawing combined with specific embodiments below.
Comparative example 1
1, hydrothermal synthesis
1,3,6- trinitro- pyrene, sodium hydroxide mixed aqueous solution in hydrothermal synthesis after a certain period of time, it is obtained molten
Liquid is purified through dialysis.Wherein, 1,3,6- trinitro- pyrene concentration are 3mmol/L, and the concentration of sodium hydroxide is 0.2mol/L, and hydro-thermal is anti-
Answering temperature is 200 DEG C, the hydro-thermal reaction time 10h.Reaction product is sufficiently dialysed through the bag filter that molecular cut off is 1000Da
Afterwards, solution in bag filter is sufficiently dialysed through the bag filter that molecular cut off is 3500Da again, the outer solution of bag filter is as anti-
Answer product.
2, characterization and detection
Above-mentioned reaction product is placed under 365nm ultraviolet light, it can be seen that 1,3,6- trinitro- pyrene and sodium hydroxide
Mixed solution products therefrom has green fluorescence (Fig. 1).
Comparative example 2
1, hydrothermal synthesis
Tryptophan, sodium hydroxide mixed aqueous solution in hydrothermal synthesis after a certain period of time, obtained solution is through dialysing
Purification.Wherein, Tryptophan concentration 20mmol/L, the concentration of sodium hydroxide are 0.1mol/L, and hydrothermal temperature is 200 DEG C,
The hydro-thermal reaction time is 10h.Reaction product, will be molten in bag filter after the bag filter that molecular cut off is 1000Da is sufficiently dialysed
Liquid is sufficiently dialysed through the bag filter that molecular cut off is 3500Da again, and the outer solution of bag filter is reaction product.
2, characterization and detection
Above-mentioned reaction product is placed under 365nm ultraviolet light, it can be seen that tryptophan and sodium hydroxide mixed solution
Products therefrom has weak green fluorescence (Fig. 2).
Embodiment 1
1, the hydrothermal synthesis of nitrogen-doped graphene quantum dot
In the mixed aqueous solution of 1,3,6- trinitro- pyrene, tryptophan and sodium hydroxide hydrothermal synthesis after a certain period of time, institute
Obtained solution is purified through dialysis.Wherein, 1,3,6- trinitro- pyrene concentration are 6mmol/L, and the concentration of tryptophan is 15mmol/L,
The concentration of sodium hydroxide is 0.15mol/L, and hydrothermal temperature is 200 DEG C, the hydro-thermal reaction time 10h.Reaction product is through cutting
Stay molecular weight be 1000Da bag filter sufficiently dialyse after, by solution in bag filter again through molecular cut off be 3500Da it is saturating
Analysis bag is sufficiently dialysed, and the outer solution of bag filter is nitrogen-doped graphene quantum dot solution.
2, characterization and detection
Ultraviolet light, x-ray photoelectron spectroscopy, atom are carried out to nitrogen-doped graphene quantum dot in specific embodiment 1
The tests such as force microscope, transmission electron microscope, fluorescence spectrum characterization, obtained Measurement results are as shown in Fig. 3~12.
The blue-fluorescence of the emitting bright under 365nm ultraviolet excitation of nitrogen-doped graphene quantum dot shown in Fig. 3.It is absolutely
Quantum yield is 23%, fluorescence lifetime 6.9ns.
Fig. 4 is photograph when mercury ion (5 μm of ol/L) is added in nitrogen-doped graphene quantum dot under 365nm ultraviolet light
Piece.As can be seen that Low Concentration Mercury ion, which is added, can quench the fluorescence of nitrogen-doped graphene quantum dot.
Fig. 5 is fluorescent quenching rate when different metal ions (25 μm of ol/L) is added in nitrogen-doped graphene quantum dot.It can be with
Find out, the fluorescence of nitrogen-doped graphene quantum dot can be quenched by mercury ion conspicuousness, including potassium ion, sodium ion, calcium ion, magnesium
Other metals including ion, zinc ion, aluminium ion, nickel ion, cobalt ions, chromium ion, lead ion, cadmium ion and silver ion from
Son all cannot significantly quench its fluorescence.This proves that nitrogen-doped graphene quantum dot of the invention has Selective recognition to mercury ion
Ability and strong active force.
Fig. 6 is the x-ray photoelectron spectroscopy figure score (A) of nitrogen-doped graphene quantum dot, C1s High Resolution Spectrum (B), O1s
High Resolution Spectrum (C), N1s High Resolution Spectrum (D).It can be seen that the atomic percent of nitrogen-doped graphene quantum dot is respectively
78.7%, 17.3% and 4.0%, this illustrates successfully to introduce N atom.Occur C=C in C1s High Resolution Spectrum, C-O/C-N and
The peak of O-C=O.Two peaks in O1s high-resolution spectrogram are respectively belonging to C-OH and C=O.Three peaks in N1s High Resolution Spectrum
Respectively pyrroles N (C-N-C), graphite N (N- (C) 3) and amino N (C-N-H) group.The presence of graphite N and pyrroles N illustrate N member
Element has successfully been doped on the carbon skeleton of GQDs.The effective conjunction of nitrogen-doped graphene quantum dot of these result valid certificates
At.
Fig. 7 is the atomic force microscopy and height distribution map of nitrogen-doped graphene quantum dot.As can be seen that average thickness
Degree is about 1.0nm.In view of the presence of the hetero atom and surface group of doping, nitrogen-doped graphene quantum dot has mono-layer graphite
Alkene structure.
Fig. 8 is the transmission electron microscope photo of nitrogen-doped graphene quantum dot.(A) icon ruler is 20nm, and (B) icon ruler is 5nm.
As can be seen that the average-size of nitrogen-doped graphene quantum dot is about 2.1nm.It can be seen that apparent carbon crystal ruling from (B) figure,
Prove that nitrogen-doped graphene quantum dot has good crystallinity.
The atomic thickness of single layer and good crystallinity show that the structure of nitrogen-doped graphene quantum dot is substantially distinguished from carbon
Point material.
Fig. 9 be nitrogen-doped graphene quantum dot excitation spectrum and 340nm to 410nm excitation wavelength under obtained transmitting light
Spectrum.As can be seen that the nitrogen-doped graphene quantum dot of synthesis has the fluorescent emission that does not depend on of excitation wavelength, when with different excitations
When wavelength is excited, fluorescent emission peak position does not emit variation, it was demonstrated that the nitrogen-doped graphene quantum dot of synthesis has monocrystalline
Property.And the half-peak breadth of its fluorescence peak is relatively narrow.The half-peak breadth of fluorescence emission spectrum under maximum excitation wavelength is about 55nm.This
As a result confirm that nitrogen-doped graphene quantum dot has uniform structure.
Figure 10 is fluorescence spectra when various concentration mercury ion being added in nitrogen-doped graphene quantum dot.It is top-down
Ion concentration of mercury is respectively 0,50nmol/L, 100nmol/L, 300nmol/L, 500nmol/L, 1 μm of ol/L, 3 μm of ol/L, 5 μ
mol/L,7μmol/L,10μmol/L,12μmol/L,15μmol/L,20μmol/L,25μmol/L.Utilize fluorescence intensity reduced rate
(ratio of fluorescence intensity in the presence of mercury ion and both fluorescence intensities when no mercury ion) and ion concentration of mercury, draw work
Curve, detection are limited to 19nmol/L.
Figure 11 is the partial size that dynamic light scattering measures when mercury ion (25 μm of ol/L) being added in nitrogen-doped graphene quantum dot
Distribution map.As can be seen that average grain diameter increases to 1 μm or more, it was demonstrated that N doping graphite in the presence of mercury ion after mercury ion is added
Alkene quantum dot is reunited.
The fluorescence lifetime of nitrogen-doped graphene quantum dot is 0.6ns in the presence of mercury ion.The reduction explanation of fluorescence lifetime
There is also electronics transfers between nitrogen-doped graphene quantum dot and mercury ion.Therefore, mercury ion by with nitrogen-doped graphene amount
Electronics transfer occurs between son point, makes to reunite between nitrogen-doped graphene quantum dot at the same time.Both effects cause
The fluorescence of nitrogen-doped graphene quantum dot reduces.
Figure 12 is fluorescence when various concentration cysteine being added in nitrogen-doped graphene quantum dot-mercury ion mixed solution
Spectrogram.Semicystinol concentration from bottom to top is respectively 0,100nmol/L, 300nmol/L, 500nmol/L, 1 μm of ol/L, 3 μ
mol/L,5μmol/L,7μmol/L,9μmol/L,10μmol/L,12μmol/L,15μmol/L,17μmol/L,20μmol/L,25
μmol/L,30μmol/L,40μmol/L,50μmol/L.Restore the percentage (fluorescence in the presence of cysteine using fluorescence intensity
Intensity and the fluorescence intensity in the presence of difference/cysteine of fluorescence intensity when no cysteine) and cysteine ion concentration,
Working curve is drawn, detection is limited to 29nmol/L.
Embodiment 2
1, the hydrothermal synthesis of nitrogen-doped graphene quantum dot
In the mixed aqueous solution of 1,3,6- trinitro- pyrene, tryptophan and sodium hydroxide hydrothermal synthesis after a certain period of time, institute
Obtained solution dialysis purifies the dry obtained graphene quantum dot solid of laggard one-step freezing.Wherein, 1,3,6- trinitro- pyrenes are dense
Degree is 4mmol/L, and the concentration of tryptophan is 20mmol/L, and the concentration of sodium hydroxide is 0.15mol/L, and hydrothermal temperature is
180 DEG C, the hydro-thermal reaction time 6h.Reaction product will dialyse after the bag filter that molecular cut off is 1000Da is sufficiently dialysed
Solution is sufficiently dialysed through the bag filter that molecular cut off is 3500Da again in bag, and the outer solution of bag filter is nitrogen-doped graphene
Quantum dot solution.
2, characterization and detection
Ultraviolet light, x-ray photoelectron spectroscopy figure, original are carried out to nitrogen-doped graphene quantum dot in specific embodiment 2
The tests such as sub- force microscope, transmission electron microscope, fluorescence spectrum characterization, nitrogen-doped graphene quantum dot prepared by embodiment 2 equally have
The fluorescent emission for having single layer structure, blue-fluorescence, excitation wavelength not to depend on, mercury ion can quench nitrogen-doped graphene quantum dot
Fluorescence.
Above embodiments are only the preferred embodiment of the present invention, and not all.Based on the implementation example in the implementation mode, originally
Field technical staff obtained other embodiments without making creative work, belong to protection model of the invention
It encloses.
Claims (8)
1. a kind of preparation method of nitrogen-doped graphene quantum dot, comprising: carbon-source cpd and nitrogen source compound is soluble in water
Mixed aqueous solution is obtained, the nitrogen-doped graphene quantum dot is made in hydro-thermal reaction under alkaline condition, which is characterized in that institute
Stating carbon-source cpd is 1,3,6- trinitro- pyrenes, and nitrogen source compound is tryptophan.
2. the preparation method of nitrogen-doped graphene quantum dot as described in claim 1, which is characterized in that the mixed aqueous solution
In the concentration of 1,3,6- trinitro- pyrenes be 0.2~8mmol/L, the concentration of tryptophan is 5~75mmol/L.
3. the preparation method of nitrogen-doped graphene quantum dot as claimed in claim 1 or 2, which is characterized in that alkaline condition by
Sodium hydroxide is adjusted, and the concentration of sodium hydroxide is 15~300mmol/L, sodium hydroxide and Tryptophan concentration ratio in reaction system
For 3:1~25:1.
4. the preparation method of nitrogen-doped graphene quantum dot as described in claim 1, which is characterized in that the hydro-thermal reaction
Temperature is 140~200 DEG C, and the time is 4~12 hours.
5. the preparation method of nitrogen-doped graphene quantum dot as described in claim 1, which is characterized in that further include utilizing dialysis
Or nitrogen-doped graphene quantum dot of the ultrafiltration retention reaction product middle-molecular-weihydroxyethyl between 1000~3500Da is to get described
Nitrogen-doped graphene quantum dot.
6. a kind of nitrogen-doped graphene quantum dot as made from claim 1-5 described in any item preparation methods.
7. application of the nitrogen-doped graphene quantum dot as claimed in claim 6 in detection mercury ion.
8. nitrogen-doped graphene quantum dot as claimed in claim 6 and the mixture of mercury ion effect detect half Guang ammonia in preparation
Application in acid reagent box.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910700815.3A CN110499155A (en) | 2019-07-31 | 2019-07-31 | A kind of nitrogen-doped graphene quantum dot and its preparation method and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910700815.3A CN110499155A (en) | 2019-07-31 | 2019-07-31 | A kind of nitrogen-doped graphene quantum dot and its preparation method and application |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110499155A true CN110499155A (en) | 2019-11-26 |
Family
ID=68588014
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910700815.3A Pending CN110499155A (en) | 2019-07-31 | 2019-07-31 | A kind of nitrogen-doped graphene quantum dot and its preparation method and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110499155A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110975919A (en) * | 2019-12-25 | 2020-04-10 | 福州大学 | Nitrogen-doped carbon quantum dot in-situ growth denitration sulfur-resistant catalyst and preparation method thereof |
| CN111551532A (en) * | 2020-06-22 | 2020-08-18 | 南通大学 | Metal ion detection method based on graphene quantum dot fluorescent probe array |
| CN112067591A (en) * | 2020-09-14 | 2020-12-11 | 江苏省农业科学院 | Nitrogen-doped graphene quantum dot fluorescent probe-based umami amino acid detection method and probe |
| CN112934132A (en) * | 2021-03-10 | 2021-06-11 | 瓮福（集团）有限责任公司 | Boron-nitrogen co-doped reduced graphene oxide aerogel and preparation method and application thereof |
| CN113209938A (en) * | 2021-04-12 | 2021-08-06 | 上海纳米技术及应用国家工程研究中心有限公司 | Preparation of gold nanoparticle @ phosphorus and sulfur co-doped graphene quantum nanocomposite with core-shell structure, product and application |
| CN115124997A (en) * | 2022-08-09 | 2022-09-30 | 西北师范大学 | Preparation of carbon quantum dot fluorescent probe and application of carbon quantum dot fluorescent probe in detection of iron ions and cysteine |
| CN115216292A (en) * | 2021-04-14 | 2022-10-21 | 中科院广州化学有限公司 | Hierarchical preparation of nitrogen-doped carbon quantum dot N @ CQDs and application of hierarchical preparation in quantitative detection of mercury ions |
| CN115465854A (en) * | 2022-09-07 | 2022-12-13 | 广东环境保护工程职业学院 | Preparation method of nitrogen-doped fluorescent carbon quantum dots and application of nitrogen-doped fluorescent carbon quantum dots to detection of mercury ions |
| CN116836701A (en) * | 2023-07-04 | 2023-10-03 | 广东药科大学 | Aluminum-doped carbon dot, preparation method, application and Hg removal method 2+ Is a method of (2) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105670618A (en) * | 2016-02-25 | 2016-06-15 | 浙江理工大学 | Sulfur-doping graphene quantum dot, preparation method of sulfur-doping graphene quantum dot and application of silver ion detection |
| CN105670619A (en) * | 2016-02-25 | 2016-06-15 | 浙江理工大学 | Sulfur-doping graphene quantum dot, preparation method of sulfur-doping graphene quantum dot and application of lead ion detection |
| CN107021476A (en) * | 2017-05-24 | 2017-08-08 | 中国药科大学 | A kind of fusion preparation method of nitrogen-doped graphene quantum dot |
| CN107236541A (en) * | 2017-07-14 | 2017-10-10 | 河北民族师范学院 | The preparation method of nitrogen-doped graphene quantum dot and the detection method of ascorbic acid |
| CN107324315A (en) * | 2017-06-07 | 2017-11-07 | 陕西科技大学 | A kind of preparation method of the graphene quantum dot based on leather castoff |
| KR20180024363A (en) * | 2016-08-30 | 2018-03-08 | 한국교통대학교산학협력단 | Multiatom co-doped quantum dot, method for producing the same and use thereof |
| CN109665514A (en) * | 2017-10-17 | 2019-04-23 | 江南大学 | A kind of Hg2+The preparation method of detection and diagnosing tumor graphene quantum dot |
-
2019
- 2019-07-31 CN CN201910700815.3A patent/CN110499155A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105670618A (en) * | 2016-02-25 | 2016-06-15 | 浙江理工大学 | Sulfur-doping graphene quantum dot, preparation method of sulfur-doping graphene quantum dot and application of silver ion detection |
| CN105670619A (en) * | 2016-02-25 | 2016-06-15 | 浙江理工大学 | Sulfur-doping graphene quantum dot, preparation method of sulfur-doping graphene quantum dot and application of lead ion detection |
| KR20180024363A (en) * | 2016-08-30 | 2018-03-08 | 한국교통대학교산학협력단 | Multiatom co-doped quantum dot, method for producing the same and use thereof |
| CN107021476A (en) * | 2017-05-24 | 2017-08-08 | 中国药科大学 | A kind of fusion preparation method of nitrogen-doped graphene quantum dot |
| CN107324315A (en) * | 2017-06-07 | 2017-11-07 | 陕西科技大学 | A kind of preparation method of the graphene quantum dot based on leather castoff |
| CN107236541A (en) * | 2017-07-14 | 2017-10-10 | 河北民族师范学院 | The preparation method of nitrogen-doped graphene quantum dot and the detection method of ascorbic acid |
| CN109665514A (en) * | 2017-10-17 | 2019-04-23 | 江南大学 | A kind of Hg2+The preparation method of detection and diagnosing tumor graphene quantum dot |
Non-Patent Citations (1)
| Title |
|---|
| 葛淑燕: "掺杂型石墨烯量子点的制备及其荧光传感研究", 《中国优秀博硕士学位论文全文数据库（硕士） 工程科技Ⅰ辑》 * |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110975919A (en) * | 2019-12-25 | 2020-04-10 | 福州大学 | Nitrogen-doped carbon quantum dot in-situ growth denitration sulfur-resistant catalyst and preparation method thereof |
| CN110975919B (en) * | 2019-12-25 | 2021-06-01 | 福州大学 | Nitrogen-doped carbon quantum dot in-situ growth denitration sulfur-resistant catalyst and preparation method thereof |
| CN111551532A (en) * | 2020-06-22 | 2020-08-18 | 南通大学 | Metal ion detection method based on graphene quantum dot fluorescent probe array |
| CN112067591A (en) * | 2020-09-14 | 2020-12-11 | 江苏省农业科学院 | Nitrogen-doped graphene quantum dot fluorescent probe-based umami amino acid detection method and probe |
| CN112067591B (en) * | 2020-09-14 | 2023-06-16 | 江苏省农业科学院 | Method for detecting delicious amino acid based on nitrogen-doped graphene quantum dot fluorescent probe and probe |
| CN112934132B (en) * | 2021-03-10 | 2023-03-03 | 瓮福（集团）有限责任公司 | Boron-nitrogen co-doped reduced graphene oxide aerogel and preparation method and application thereof |
| CN112934132A (en) * | 2021-03-10 | 2021-06-11 | 瓮福（集团）有限责任公司 | Boron-nitrogen co-doped reduced graphene oxide aerogel and preparation method and application thereof |
| CN113209938A (en) * | 2021-04-12 | 2021-08-06 | 上海纳米技术及应用国家工程研究中心有限公司 | Preparation of gold nanoparticle @ phosphorus and sulfur co-doped graphene quantum nanocomposite with core-shell structure, product and application |
| CN115216292A (en) * | 2021-04-14 | 2022-10-21 | 中科院广州化学有限公司 | Hierarchical preparation of nitrogen-doped carbon quantum dot N @ CQDs and application of hierarchical preparation in quantitative detection of mercury ions |
| CN115216292B (en) * | 2021-04-14 | 2024-01-09 | 中科院广州化学有限公司 | Graded preparation of nitrogen-doped carbon quantum dots N@CQDs and application of graded preparation in quantitative detection of mercury ions |
| CN115124997A (en) * | 2022-08-09 | 2022-09-30 | 西北师范大学 | Preparation of carbon quantum dot fluorescent probe and application of carbon quantum dot fluorescent probe in detection of iron ions and cysteine |
| CN115465854A (en) * | 2022-09-07 | 2022-12-13 | 广东环境保护工程职业学院 | Preparation method of nitrogen-doped fluorescent carbon quantum dots and application of nitrogen-doped fluorescent carbon quantum dots to detection of mercury ions |
| CN115465854B (en) * | 2022-09-07 | 2024-01-30 | 广东环境保护工程职业学院 | Preparation method of nitrogen-doped fluorescent carbon quantum dot and detection application of nitrogen-doped fluorescent carbon quantum dot to mercury ions |
| CN116836701A (en) * | 2023-07-04 | 2023-10-03 | 广东药科大学 | Aluminum-doped carbon dot, preparation method, application and Hg removal method 2+ Is a method of (2) |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110499155A (en) | A kind of nitrogen-doped graphene quantum dot and its preparation method and application | |
| CN108456519B (en) | Nitrogen-doped fluorescent carbon quantum dot and preparation method thereof | |
| CN110184052B (en) | Biomass-based efficient fluorescent graphene quantum dot and preparation method thereof | |
| Landa et al. | Heavy metal ion detection using green precursor derived carbon dots | |
| Wang et al. | Highly luminescent N, S-Co-doped carbon dots and their direct use as mercury (II) sensor | |
| CN105670618B (en) | A kind of application of sulfur doping graphene quantum dot and preparation method thereof and detection silver ion | |
| Hou et al. | One-pot electrochemical synthesis of functionalized fluorescent carbon dots and their selective sensing for mercury ion | |
| Gaddam et al. | Controllable synthesis of biosourced blue-green fluorescent carbon dots from camphor for the detection of heavy metal ions in water | |
| Atchudan et al. | Eco-friendly synthesis of tunable fluorescent carbon nanodots from Malus floribunda for sensors and multicolor bioimaging | |
| CN110938430A (en) | Silicon and nitrogen co-doped carbon quantum dot and preparation method and application thereof | |
| CN105199716B (en) | 3 mercaptopropionic acid bovine serum albumin(BSA) gold nano clusters and preparation method thereof | |
| Mao et al. | Gram-scale synthesis of nitrogen doped graphene quantum dots for sensitive detection of mercury ions and L-cysteine | |
| CN103361047A (en) | Functional fluorescence carbon nanoparticles based on natural saccharide materials and preparation method and application thereof | |
| Wu et al. | Generation of nitrogen-doped photoluminescent carbonaceous nanodots via the hydrothermal treatment of fish scales for the detection of hypochlorite | |
| CN108998012B (en) | Blue fluorescent quantum dot, preparation method thereof and copper ion detection application | |
| CN106893585B (en) | Metal manganese doped carbon quantum dot with high fluorescence quantum yield and preparation method and application thereof | |
| CN109248680B (en) | Low-energy-consumption chemical field-driven organic pollutant degradation catalyst and application thereof | |
| CN103160279A (en) | Functional carbon dots, and preparation and application thereof | |
| CN105255487B (en) | Amino alcohol functional CDs (carbon dots), preparation method and application of amino alcohol functional CDs in copper ion measurement | |
| CN105670619A (en) | Sulfur-doping graphene quantum dot, preparation method of sulfur-doping graphene quantum dot and application of lead ion detection | |
| CN106053408A (en) | Carbon dot fluorescent probe based high sensitive and high selective method for detecting trace silver nano particles in water and/or environment | |
| Zhao et al. | One-step synthesis of S, B co-doped carbon dots and their application for selective and sensitive fluorescence detection of diethylstilbestrol | |
| Ghosh et al. | Current scenario and recent advancement of doped carbon dots: a short review scientocracy update (2013–2022) | |
| CN113148979A (en) | Method for preparing carbon dots with different colors under same wavelength by using tobacco waste and application | |
| Han et al. | Efficient one-pot synthesis of carbon dots as a fluorescent probe for the selective and sensitive detection of rifampicin based on the inner filter effect |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20191126 |
|
| WD01 | Invention patent application deemed withdrawn after publication |