WO2022073099A1 - Metalized nano coated swab for trace detection - Google Patents

Abstract

The present invention provides a swab comprising a substrate material and a metal coating. Also provided are methods of manufacturing the swab. The swab may be used for collection of trace analyte samples including explosives and narcotics.

Description

METALIZED NANO COATED SWAB FOR TRACE DETECTION

FIELD OF THE INVENTION

The present invention relates to chemical trace detection. In particular, the present invention relates to swabs for collection of samples for trace detection.

BACKGROUND OF THE INVENTION

Trace analyte detection is the detection of small amounts of analytes, often at nanogram to picogram levels. Trace analyte detection has numerous applications, such as screening individuals and baggage at transportation centers, mail screening, facility security applications, military applications, forensics applications, narcotics detection and identification, cleaning validation, quality control, and raw material identification. Trace analyte detection can be particularly useful for security applications such as screening individuals or items for components in explosive materials, narcotics or biological contaminants where small amounts of these components are deposited on the individual or on the outside of a package or bag.

The effectiveness of trace analysis is highly dependent on three distinct steps: (1) sample collection by swab (Trap); (2) sample analysis; and (3) comparison of results with known standards. If any of these steps is suboptimal, the test may fail to detect explosives that are present.

Swabs are designed to harvest particles from surfaces (like as container, luggage, bag, etc.) for analysis by the trace detection instrument. The sample collection process entails the use of specific procedures regarding the item to be sampled with trap passes proceeding in a logical fashion across the item to be swabbed to ensure complete sample gathering. Explosive Trace Detection (ETD) swabs material is designed for use in the ETD device which requires high temperatures to burn off trace elements for identification by the system. Trace detection is based upon the chemical analysis of explosive residues resulting from bomb building or concealment or any encounter with the components of explosives. Similarly, narcotic trace detection is predicated upon the chemical analysis of subject encounters with narcotic component.

Detection accuracy and reliability is challenging due to very low amount of trace material for detection. In addition, detection technologies, such as mass spectrometry, gas chromatography, chemical luminescence, or ion mobility spectrometry, measure the chemical properties of vapor for detection. These technologies use heat to vapor explosive chemical (up to 300°C) which makes heat transferring of swabs critical for detection process.

Swaps which are currently available in the market, they have very low collecting efficiency (harvesting) and heat transferring properties

This background information is provided for the purpose of making known information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a metalized nano coated swab for trace detection.

In accordance with an aspect of the present invention, there is provided a swab comprising a substrate material and a coating. In certain embodiments, the substrate is nonwoven, woven or a film. In certain embodiments, the coating is a metal. In certain embodiments, the coating is a high surface energy material. In certain embodiments, the coating has high thermal conductivity properties. In certain embodiments, the coating is a metal selected from the group consisting of copper, aluminum, silver, gold and combinations thereof.

In accordance with another aspect of the present invention, there is provided a method of manufacturing the swab comprising coating a substrate with a metal. In certain embodiments, coating is by vapor deposition, E beam deposition or sputtering.

In accordance with another aspect of the present invention, there is provided a swab produced by the methods of the invention.

In accordance with another aspect of the present invention, there is provided a method of collecting trace analyte samples, the method comprising contacting a surface with the swab of the invention. In certain embodiments, the analyte is an explosive. In certain embodiments, the analyte is a narcotic.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the invention will become more apparent in the following detailed description in which reference is made to the appended drawings. Figure 1 presents a nonwoven substrate with more surface area.

Figure 2 presents a close up view of a nonwoven substrate with more surface area.

Figure 3 presents surface energy of different materials.

Figure 4 presents thermal conductivity of different materials.

Figure 5 presents a metallizing process which utilizes vapor deposition

Figure 6 presents a metallizing process which utilizes sputtering.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a coated material, e.g. a coated swab, which may be used for sample collection in trace analyte detection.

Trace detection reliability and accuracy may be improved by improving the collection (harvesting) capabilities of the swab used for sample collection and/or improving the transferring properties of the swab used for sample collection. Accordingly, in certain embodiments, the swabs of the present invention have improved collecting efficiency (harvesting) as compared to uncoated swabs (manufactured from the same material as the substrate material of the coated swab). In certain embodiments, the swabs of the present invention have improved transferring properties as compared to uncoated swabs. In certain embodiments, the swabs of the present invention have improved collecting efficiency (harvesting) and improved transferring properties as compared to uncoated swabs.

Swab

The swab of the present invention comprises a substrate material and a coating.

The substrate may be nonwoven, woven or a film. Exemplary materials include but are not limited to cotton, Nomex® and polyamide membrane surfaces.

Other exemplary materials include but are not limited to polyester point bonded, Spunlace, needlepunch nonwoven with (30 up to 250 gsm).

A swab’s harvesting efficiency is in part related to surface roughness. In particular, swabs with a rough surface will likely collect more trace material due to increased surface area as compared to a swab of the same size having a smooth surface. A worker skilled in the art would readily appreciate that the surface roughness may be impacted by the components of the substrate and the manufacturing process of the substrate. For example, the surface roughness of a woven substrate may be impacted by the fiber used and/or the weave. The surface roughness of non-woven fibrous materials may be impacted by the fiber used and/or manufacturing process. Mechanical or chemical treatments may be used to enhance surface roughness of films.

The substrate is coated with a coating. In certain embodiments the coating is a metal. The metal may be one metal or a combination of metals.

A swab’s harvesting efficiency is also in part related to its surface energy. A swab’s surface energy may be increase by coating the surface with a High Surface Energy Material. Exemplary materials include but are not limited metals such as aluminum, copper, silver, gold and zinc. (Table 1 - Surface Energy). Accordingly, in certain embodiments, the coating is a high surface energy material. In certain embodiments, the high surface energy material is a metal. In specific embodiments, the metal is selected from the group consisting of aluminum, copper, silver, gold, zinc and combinations thereof.

Typical detection technique involves thermally driving a sample into a detector. Accordingly, swabs with higher heat transferring may improve the detection process. Accordingly, in certain embodiments, the coating has high thermal conductivity properties. In certain embodiments, the material having high thermal conductivity properties is a metal. In specific embodiments, the metal is selected from the group consisting of copper, aluminum, silver, gold and combinations thereof.

In certain embodiments, the coating material is a metal with high surface energy and high thermal conductivity. In certain embodiments, the coating is a metal selected from the group consisting of copper, aluminum, silver, gold and combinations thereof.

Method of Manufacturing the Swab

The present invention further provides a method of manufacturing the swab. The method comprises coating the substrate with a metal. In certain embodiments, vacuum coating is used to coat the substrate. A variety of techniques are known in the art to coat a substrate. In certain embodiments, the methods are performed under low pressure. In specific embodiments, the methods are performed in an ultra low-pressure vacuum chamber. Nonlimiting examples include but are not limited to vapor deposition, E-beam and sputtering

In certain embodiments, the method comprises coating the substrate with a metal by vapor deposition. A worker skilled in the art would readily appreciate that the process of vapor deposition involves heating a piece of metal to its boiling point and allowing the metal vapor to settle on a passing substrate. An exemplarily process of vapor deposition is described below. Briefly, metal (such as a metal wire) is fed into a heated tub causing it to melt. Because of the low chamber pressure, the melting point of the metal wire is far lower than it would be under normal conditions. When the metal boils, a vapor is formed which will adhere to a piece of substrate passing through the chamber. The amount of metal applied to the substrate is determined by the speed at which the substrate passes through the chamber. By adjusting speeds, the density of the metal applied to the substrate may be altered. This allows for the creation of swabs with varying degrees of metallization. Generally speaking, the longer the exposure to vapor, the thicker the metal coating on the substrate.

In certain embodiments, the method comprises coating the substrate with a metal by E beam deposition. A worker skilled in the art would readily appreciate that this process is similar to the vapor deposition procedure except the metal is not placed in a heated tub. Instead, an electron beam is used to heat the metal wire.

In certain embodiments, the method comprises coating the substrate with a metal by sputtering. As in vapor deposition, a low-pressure vacuum chamber is used to create a gas atmosphere. Electrical energy is then used to create a negative charge to the gas molecules. The vacuum pressure allows the subsequent gas molecule particles to move freely and rapidly about the chamber. When these charged particles collide with a metal “cathode”, small particles of the metal are chipped off the cathode and subsequently deposited on the substrate. Similar to the vapor coating method, the speed at which the substrate travels through the chamber determines the density of the metal on the substrate.

Uses

The swabs of the present invention are useful for collecting samples containing of a wide range of analytes, including but not limited to explosives, narcotics, chemical warfare agents, toxins, pharmaceutical process contaminants, and other chemical compounds.

In certain embodiments, the swab is for collection of samples for trace explosive detection. Explosives which may be collected using a swab include, but are not limited to, 2-amino-4,6- dinitrotoluene, 4-amino-2,6-dinitrotoluene, ammonal, ammonium nitrate, black powder, 2,4- dimethyl-1 ,3-dinitrobutane, 2,4-dinitrotoluene, ethylene glycol dinitrate, forcite 40, GOMA-2, hexanitrostilbene, 1 ,3,5,7-tetranitro-1 ,3,5,7-tetrazacyclooctane (HMX), mononitrotoluene, nitroglycerine, pentaerythritol tetranitrate (PETN), 1 ,3,5-trinitro-1 ,3,5-triazacyclohexane (RDX), semtex-A, Semtex-H, smokeless powder, trinitro-2,4,6-phenylmethylnitramine tetryl (Tetryl), 2,4,6-trinitrotoluene (TNT), trilita, and 1 ,3,5-trinitrobenzene and combinations of these compounds. In one embodiment, the explosive which are collected are 1 ,3,5-trinitro- 1 ,3,5-triazacyclohexane, pentaerythritol tetranitrate, 2,4,6-trinitrotoluene, trinitro-2,4,6- phenylmethylnitramine tetryl, nitroglycerine, ammonium nitrate, 3,5,7-tetranitro-1 ,3,5,7- tetrazacyclooctane, and combinations thereof.

In certain embodiments, the swab is for collection of samples for trace narcotic detection. Narcotics which may be collected using a swab include, but are not limited to 6- acetylmorphine, alprazolam, amobarbital, amphetamine, antipyrine, benzocaine, benzoylecgonine, bromazepam, butalbital, carbetapentane, cathinone, chloradiazepoxide, chlorpheniramine, cocaethylene, ***e, codeine, diazepam, ecgonine, ecognine methyl ester (EME), ephedrine, fentanyl, flunitrazepam, hashish, heroin, hydrocodone, hydromorphone, ketamine, lidocaine, lorazepam, lysergic acid diethylamide (LSD), lysergic acid, N-methyl-1-3(3,4-methylenedioxyohenyl)-2-butanamine (MBDB), 3,4- methylenedioxyamphetamine (MDA), DL-3,4-methylenedioxyethylamphetamine (MDEA), methylenedioxymethamphetamine (MDMA), marijuana, mescaline, methadone, methamphetamine, methaqualone, methcathinone, morphine, noscapine, opium, oxazepam, oxycodone, phencyclidine (PCP), pentobarbital, phenobarbital, procaine, psilocybin, secobarbital, temazepam, THC, THC-COOH, and triazolam. In one embodiment, the narcotics which can be collected with a swab include ***e, heroin, phencyclidine, THC, methamphetamine, methylenedioxyethylamphetamine, methylenedioxymethamphetamine, N-methyl-1-3(3,4-methylenedioxyohenyl)-2-butanamine, lysergic acid diethylamide, and combinations thereof.

In certain embodiments, the swab is for collection of samples for trace detection of chemical warfare agents and other toxins. Chemical warfare agents and other toxins that may be collected using a swab include, but are not limited to amiton (VG), anthrax, arsine, cyanogen chloride, hydrogen chloride, chlorine, diphosgene, PFIB, phosgene, phosgene oxime, chloropicrin, ethyl N,N-dimethyl phosphoramicocyanidate (Tabun), isopropyl methyl phosphonofluoridate (Sarin), pinacolyl methyl phosphonefluoridate (Soman), phosphonofluoridic acid, ethyl-, isopropyl ester (GE), phosphonothioic acid, ethyl-, S-(2- (diethylamino)ethyl) O-ethyl ester (VE), phosphonothioic acid, methyl-, S-(2- (diethylamino)ethyl) O-ethyl ester (VM), distilled mustard, ethyldichloroarsine, lewisite 1 , lewisite 2, lewisite 3, methyldichloroarsine, mustard-lewisite mixture, mustard-T mixture, nitrogen mustard 1 , nitrogen mustard 2, nitrogen mustard 3, phenyldichloroarsine, phosgene oxime, sesqui mustard, adamsite, aflatoxin, botulinus toxin, ricin, saxitoxin, trichothecene mycotoxin, methylphosphonothioic acid S-(2-(bis(1-methylethyl)amino)ethyl) O-ethyl ester (VX), cyclohexyl methylphosphonofluoridate (GF), and combinations thereof. Sample analytes can be collected onto a swab by any suitable means. For example, a sample containing analytes of interest can be collected onto a swab by direct contact of the swab with the surface to be tested, e.g., by mechanical agitation or frictional contact. Direct contact can be achieved by direct manual contact of an article with the swab or insertion of swab material into a holder which manually or automatically directly contacts an article with the swab material.

A surface to be tested can include any surface of a person or object. For example, the surface can be a surface of a personal effect, clothing, bag, luggage, furniture, automobile interior, pharmaceutical process equipment, etc.

Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention. All such modifications as would be apparent to one skilled in the art are intended to be included within the scope of the following claims.

Claims

WE CLAIM:

1. A swab comprising a substrate material and a coating.

2. The swab of claim 1 , wherein the substrate is nonwoven, woven or a film.

3. The swab of claim 1 or 2, wherein the coating is a metal.

4. The swab of any one of claims 1 to 3, wherein the coating is a high surface energy material.

5. The swab of any one of claims 1 to 4, wherein the coating has high thermal conductivity properties.

6. The swab of any one of claims 1 to 5, wherein the coating is a metal selected from the group consisting of copper, aluminum, silver, gold and combinations thereof.

7. A method of manufacturing the swab comprising coating a substrate with a metal.

8. The method of claim 7, wherein said coating is by vapor deposition, E beam deposition or sputtering.

9. A swab produced by the method of claim 7 or 8.

10. A method of collecting trace analyte samples, said method comprising contacting a surface with the swab of any one of claims 1 to 6.

11. The method of claim 10, wherein said analyte is an explosive.

12. The method of claim 10, wherein said analyte is a narcotic.

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