WO2019123442A1

WO2019123442A1 - Sers detection device

Info

Publication number: WO2019123442A1
Application number: PCT/IL2017/051369
Authority: WO
Inventors: Avner AVIDAN; Yair MONETA
Original assignee: Inspecto Solutions Ltd.
Priority date: 2017-12-20
Filing date: 2017-12-20
Publication date: 2019-06-27

Abstract

The present invention relates to devices that utilize Surface-enhanced Raman spectroscopy techniques for detection of at least one food contaminant, in a single automated scan.

Description

SERS DETECTION DEVICE

TECHNOLOGICAL FIELD

The present invention is in the field of Surface-enhanced Raman spectroscopy detection devices.

BACKGROUND ART

References considered to be relevant as background to the presently disclosed subject matter are listed below:

Chen, J., Huang, Y., Kannan, P., Zhang, L., Lin, Z., Zhang, J., & Guo, L. (2016). Flexible and adhesive surface enhance Raman scattering active tape for rapid detection of pesticide residues in fruits and vegetables. Analytical chemistry, 88(4), 2149-2155.

Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.

BACKGROUND

Chen, J., et al. described surface enhance Raman scattering (SERS) substrate adapted for extraction and detection of target molecules. A tape with colloidal gold nanoparticles (Au NPs) was utilized as substrate. The SERS tape was contacted with pesticide solution, dried, fixed and examined by Raman spectrometer.

However, there still remains a need for a single, easy to use device that can provide reliable and immediate readings of the type and amount of agents, such as for example pesticides, on a surface of an object, for example an edible object to be consumed by an individual.

GENERAL DESCRIPTION

The present invention provides a detection device comprising: (a) at least one sample collecting unit; (b) at least one SERS tape unit; (c) at least one wetting unit; (d) at least one spectrometer detection unit; (e) at least one display unit; wherein all units are configured in a single device; and wherein said device is adapted for detecting at least one of a pesticide, a herbicide, a fertilizer, a food contaminant or any combination thereof; on a surface exposed thereto.

The term "detection device" should be understood as a device wherein all units are configured for detecting at least one of a pesticide, a herbicide, a fertilizer, a food contaminant or any combination thereof on a surface exposed thereto. The said device is a single integral device comprising all its units in a single object which is adapted for manual operation by a user and provides a reliable and quick detections, (for example within 5 min or less), with high accuracy (for example of up to 1 ppm of the agent to be detected and/or according to the regulatory requirements of acceptable intake levels of tolerable concentrations of contaminants to be detected).

The maximum concentrations of contaminants allowed by legislation are often well below toxicological tolerance levels, because such levels can often be reasonably achieved by using good agricultural and manufacturing practices. Regulatory officials, in order to combat the dangers associated with foodborne viruses, are pursuing various possible measures. For example: EFSA report on“scientific opinion regarding an update of the present knowledge on the occurrence and control of foodborne viruses”, the European Committee for Standardization (CEN), CODEX Committee on Food Flygiene (CCFH), European Commission Regulation (EC) No 2073/2005 of 15 November 2005.

In further embodiments the detection device comprising at least one drying unit.

The term "surface" refers to the upper or outer part of an object. In some embodiments the surface is a food item surface area. In some embodiments the surface is selected from vegetable surface area or fruit surface area.

The term "object" refers to a food object to be consumed by a subject. The term "sample collecting unit" should be understood to encompass at least one unit wherein a sample of the surface of an object to be examined is collected. Such a unit may include an area within which said SERS tape is adapted to be in contact with the surface of the object to be examined thereby collecting a sample of the compounds on the surface of said object. In some embodiments, said sample collecting unit is a fixed area window, wherein the SERS tape is exposed to become in contact with the surface of said object. In some further embodiments, said sample collecting unit includes means for moving said SERS tape along the detection path of said device allowing a new SERS tape area to be exposed on the one hand and on the other hand moves the area that was exposed to the surface of said object to the spectrometer detection unit.

In some embodiments the at least one sample collecting unit has the dimensions of 1 xl cm² to lOxlOcm².

The term "SERS tape unit" should be understood to encompass at least one unit comprising a SERS enabling substrate, which can be any tape or film which is a continuous, thin flexible strip of material (either comprising an adhesive surface, or a porous paper surface) that is coated with nano particles. The said tape is adapted for washing and drying the film comprises any one of or combination of plastic, organic, glass, silicon, paper, cotton, polymer film. The adhesive may be also used to extract a sample from the object to be tested. The SERS tape becomes in contact with the surface of said object and thereby collecting a sample of the compounds on the surface of said object. See also Anal. Chem., 2016, 88 (4), pp 2149-2155.

In some embodiments the at least one adhesive surface unit passes through said at least one sample collecting unit.

The term "passes through" relates to the state in which the adhesive surface of the SERS tape unit is physically located within said fixed area window, wherein the SERS tape is exposed to become in contact with the surface of said object. In some embodiments the SERS tape is folded and\or rolled within said detection device.

In some embodiments the tape is a multilayer tape or film.

The term "nano-particles” refers to densely packed metallic nanostructures arranged in a layer of isolated metal islands used to enable surface plasmon resonance and thereby enhance the Raman- scattered light. In some embodiments said nanoparticles are gold or silver nanoparticles of any combinations thereof. In other embodiments, the nano-particles are selected with respect to the substance to be detected (such as for example pesticides, herbicide, over-fertilizers, and\or cross contaminants) that are suspected to be found on said surface of said object.

In some embodiments the SERS tape unit absorbed with nano-particles is installed within a cartridge, said cartridge is configured to be received by the detection device.

In some embodiments said cartridge is disposable

The term "wetting unit” should be understood to encompass at least one unit comprising at least one hquid solvent or a combination of solvents (for example organic solvents such as organic alcohols, organic ketones and so forth). Said unit allows for the wetting of the surface of said SERS tape, so that the solvent uniformly permeate the tape.

In some embodiments said at least one wetting unit is located before said at least one sample collecting unit. In some embodiments the said at least one wetting unit is located after said at least one sample collecting unit. In some embodiments the said at least one wetting unit is located before said at least one sample collecting unit.

The term "spectrometer detection unit” refers to a unit that measures and records a spectrogram of light to be analyzed. In some embodiments the at least one "spectrometer detection unit" comprises at least one Surface Enhanced Ramen Spectrometer (SERS) spectrophotometer, comprising an excitation source, sampling apparatus and a detector. Said Raman spectrometer identifies and quantifies the analyte based on scattered light.

In some embodiments the excitation source is a monochromatic light source having a predetermined frequency.

In some embodiments the excitation source is a laser.

In some embodiments the detector is a real-time-full frame charge couple detector CCD detector.

In some embodiments the SERS detection unit further comprises a set of optics configured to collect light scattered by the illuminated sample and directing said hght to the said detector.

In some embodiments the at least one SERS detection unit further comprises at least one SERS signal analysis unit wherein the unit received a spectra and outputs the identity and\or concentration of pesticides, herbicide, over-fertilizers, and\or cross contaminants of the surface of an object.

In some embodiments the detection device is capable of detecting residues of at least one type of pesticide. In some other embodiments the detection device is capable of detecting residues of at least one type of food contaminant.

When referring to the phrase“adapted for detecting at least one of a pesticide, a herbicide, a fertilizer, a food contaminant or any combination thereof’ it should be understood that the device of the invention is equipped with a SERS tape and spectrometer that are able to detect said at least one of a pesticide, a herbicide, a fertilizer, a food contaminant or any combination thereof, using SERS technique that is able to provide enhances Raman scattering (by molecules adsorbed on said SERS surface or by nano particles or nanostructures such as plasmonic-magnetic silica nanotubes thereon) of said contaminants and a spectroscopic unit that is able to provide readings of such contaminants. The enhancement factor of the SERS tape can be as much as 10¹⁰ to 10¹¹, which means the device of the invention may detect single molecule of said at least one contaminant.

The term‘‘ food contaminants” refer to any type of agent that exists in articles of consumption and which will present of harmful effect on the subjects that consume the article. Such food contaminants may be chemical (both solid or liquid) and microorganisms which can cause illness. The impact of chemical contaminants on consumer health and well-being is often apparent only after many years of processing. Prolonged exposure at low levels (e.g., cancer). Chemical contaminants present in foods are often unaffected by thermal processing (unlike most microbiological agents). Chemical contaminants can be classified according to the source of contamination and the mechanism by which they enter the food product.

Food contaminants include, but are not limited to: (i) agrochemicals are chemicals used in agricultural practices and animal husbandry with the intent to increase crops and reduce costs. Such agents include pesticides (e.g., insecticides, herbicides, rodenticides), plant growth regulators, veterinary drugs (e.g., nitrofuran, fluoroquinolones, malachite green, chloramphenicol), and bovine somatotropin (rBST); (ii) environmental contaminants are chemicals that are present in the environment in which the food is grown, harvested, transported, stored, packaged, processed, and consumed. The physical contact of the food with its environment results in its contamination. Possible sources of contamination include: air: radionuclides (¹³⁷Caesium, ⁹⁰Strontium), polycyclic aromatic hydrocarbons (PAH), water: arsenic, mercury, soil: cadmium, nitrates, perchlorates, Polychlorinated biphenyls (PCB), dioxins, and polybrominated diphenyl ethers (PBDE) are ubiquitous chemicals, packaging materials: antimony, tin, lead, perfluorooctanoic acid (PFOA), semicarbazide, benzophenone, isopropyl thioxanthone (ITX), bisphenol A, processing/cooking equipment: copper, or other metal chips, lubricants, cleaning, and sanitizing agents, naturally occurring toxins: mycotoxins, phytohaemagglutinin, pyrrolizidine alkaloids, grayanotoxin, mushroom toxins, scombrotoxin (histamine), ciguatera, shellfish toxins (see shellfish poisoning), tetrodotoxin, among many others; (iii) pesticides or carcinogens found in foods; (iv) processing contaminants are generated during the processing of foods (e.g., heating, fermentation). They are absent in the raw materials, and are formed by chemical reactions between natural and/or added food constituents during processing. The presence of these contaminants in processed foods cannot be entirely avoided. Technological processes can be adjusted and/or optimized, however, in order to reduce the levels of formation of processing contaminants. Examples are: nitrosamines, polycyclic aromatic hydrocarbons (PAH), heterocyclic amines, histamine, acrylamide, furan, benzene, trans fat, 3-MCPD, semicarbazide, 4- hydroxynonenal (4-HNE), and ethyl carbamate. There is also the possibility of metal chips from the processing equipment contaminating food. While many food contaminants have been known for decades, the formation and presence of certain chemicals in foods has been discovered relatively recently. These are the so-called emerging food contaminants such as acrylamide, furan, benzene, perchlorate, perfluorooctanoic acid (PFOA), 3-monochloropropane-l ,3-diol(3-MCPD), 4-hydro xynonenal, and (4-HNE).

The term "pesticides" refers to any biocide selected from fungicides, bacteriocides, antimicrobial, disinfectants, insecticides, insect growth regulators, miticides, molluscicides, repellents, rodenticides, algicides, disinfectants, nematicides, ovicides, pheromones, attractants, synergists and any combinations thereof

In some embodiments said at least one pesticide is of chemical or biological source (biopesticide).

In some embodiments the pesticides are organic or synthetic.

In some embodiments the detection device is capable of detecting residues of at least one type of herbicides.

In some embodiments the at least one type of pesticide is selected from Fenthion, Acteamiprid and Cypermethrin and any combinations thereof. The term "herbicides" refers to any chemical compound which kills or inhibits growth of plants.

In some embodiments said at least one herbicide is of chemical or biological source (bioherbicide).

In some embodiments the herbicide is organic or synthetic.

In some embodiments the detection device is capable of detecting residues of at least one type of over-fertilization.

The term "fertilizer” refers to any compound that is applied for the supply of nutrients essential to the growth of a plant.

In some embodiments the fertilizer is a single nutrient fertilizer.

In some embodiments the fertilizer is a multinutrient fertilizer.

In some embodiments the fertilizer is a micronuriant.

In some embodiments the fertilizer is selected from; nitrogen fertilizer, phosphate fertilizer, potassiumfertilizer, calcium fertilizer, magnesium fertilizer, sulful fertilizer, or any combination thereof.

In some embodiments the fertilizer is organic or synthetic fertili er.

The term "over-fertilization" refers to the over-use of a fertilizer.

In some embodiments the detection device is capable of detecting residues of at least one type of cross contaminants. The term "cross contamination" relates to the transfer of microorganism from one object to another.

In some embodiments the at least one type of pesticide is detected at levels below 1 PPM(mg/L)

In some embodiments the at least one type of pesticide is detected on a surface of a food item.

In some embodiments the detection occurs within 300 sec

In some embodiments the detection is automated, that is without continuous intervention from the user.

In some embodiments the detection is serial, that is a series of at least 2 detections can be obtained sequentially.

In some embodiments the at least one SERS detection unit sends to said at least one display unit said signal analysis.

The term " 'display unit” refers to a device with a screen that displays the measures\analyzed amount of pesticides, herbicide, over-fertilizers, and\or cross contaminants that are on said surface of said object.

In some embodiments the display unit is integral to the detection device.

In some embodiments the display unit is located at a distant environment.

In a further aspect the invention a detection device comprising: (a) at least one sample collection and preparation unit; (b) at least one SERS tape unit; (d) at least one spectrometer detection unit; (e) at least one display unit; wherein all units are configured in a single device; and wherein said device is adapted for detecting at least one of a pesticide, a herbicide, a fertilizer, a food contaminant or any combination thereof from a single sample collected.

When referring to a “ sample collection and preparation unit” it should be understood to encompass at least one unit wherein a sample of the object to be examined is collected and prepared for detecting using the SERS technique. Such a unit may include an area within which said SERS tape is adapted to be in contact with the sample taken from the object to be examined. In some embodiments, said sample preparation unit is a collector utensil that allows for collecting a sample from the object, either from its surface (for example the surface of a food article), close to its surface (peel of food article) or below its surface (at least a part of the substance, body of food article).

The SERS tape is exposed to become in contact with the collected sample of the object. In some further embodiments, said sample preparing unit includes means for moving said SERS tape along the detection path of said device allowing a new SERS tape area to be exposed on the one hand and on the other hand moves the area that was exposed to the sample of said object to the spectrometer detection unit.

The term "SERS tape unit" should be understood to encompass at least one unit comprising a SERS enabling substrate, which can be any tape or film which is a continuous, thin flexible strip of material (either comprising an adhesive surface, or a porous paper surface) that is coated with nano particles. The said tape is adapted for washing and drying the film comprises any one of or combination of plastic, organic, glass, silicon, paper, cotton, polymer film. The adhesive may be also used to obtain at least a part of the sample collected in the sample collection and preparation unit. The SERS tape becomes in contact with the sample collected. See also Anal. Chem. , 2016, 88 (4), pp 2149-2155.

In some embodiments the at least one adhesive surface unit passes through said at least one sample preparing unit. The term "passes through" relates to the state in which the adhesive surface of the SERS tape unit is physically located wherein the SERS tape is exposed to become in contact with the sampleof said object. In some embodiments the SERS tape is folded and\or rolled within said detection device.

In some embodiments the tape is a multilayer tape or film.

In some embodiments said cartridge is disposable

In some embodiments said at least one wetting unit is located before said at least one sample preparing unit. In some embodiments the said at least one wetting unit is located after said at least one sample preparing unit. In some embodiments the said at least one wetting unit is located before said at least one sample preparing unit.

In some embodiments the excitation source is a laser.

In some embodiments, a detection device of the invention is capable of detecting at least two food contaminants from a single sample of an object examined. In other embodiments, a detection device of the invention is capable of detecting at least three food contaminants from a single sample of an object examined. In further embodiments, a detection device of the invention is capable of detecting at least four food contaminants from a single sample of an object examined. DETAILED DESCRIPTION OF EMBODIMENTS

The embodiment device of the invention includes a wetting agent wherein a sponge comprising a solvent combination of ethanol and water wets a commercial SERs paper substrate before it is automatically driven on a wheel system to contact a predetermined area (the sample window) of the surface of an edible object to be tested (for example fruit or vegetable). The SERS tape is maintained on the surface of the subject to be tested for a few second until enough sample is collected. Then the SERs tape is driven using a wheel system to face a laser of the detecting unit. Thereafter the SERS is illuminated by the laser and a reading is taken by the Raman system. Then a spectrum is obtained with the Raman system and it is immediately compared to a unique Raman/SERs pesticide database. The software enables (1) a qualitative analysis of the identity of the detectable substance, wherein a spectrum comparison between the unknown sample and a database searching for a match based on predesignated requirements, and (2) a quantitative assessment of the amount of the substance detected. Finally, the device displays the results to the user on a display unit (or can also send the results to a display unit in a remote device).

Claims

CLAIMS:

1. A detection device comprising:

(a) at least one sample collecting unit;

(b) at least one SERS tape unit;

(c) at least one wetting unit;

(d) at least one spectrometer detection unit;

(e) at least one display unit;

wherein all units are configured in a single device; and

wherein said device is adapted for detecting at least one of a pesticide, a herbicide, a fertilizer, a food contaminant or any combination thereof on a surface exposed thereto.

2. A detection device according to claim 1 , wherein said at least one SERS tape unit comprises at least one flexible tape.

3. A detection device according to claim 1 , wherein said at least one wetting unit comprises at least one organic solvent.

4. A detection device according to claim 3, wherein said at least one wetting unit further comprises water.

5. A detection device according to claim 1, wherein said at least one wetting unit is located before said at least one sample collecting unit.

6. A detection device according to claim 1, wherein said at least one wetting unit is located after said at least one sample collecting unit.

7. A detection device according to claim 1 , further comprising at least one drying unit.

8. A detection device according to claim 1, wherein said at least one sample collecting unit has the dimensions of 1 xl cm² to lOxlOcm².

9. A detection device according to claim 1 , wherein said at least one adhesive surface unit passes through said at least one sample collecting unit.

10. A detection device according to claim 1 , wherein said at least one SERS detection unit comprises at least one SERS spectrophotometer.

11. A detection device according to claim 1 , wherein said at least one SERS detection unit further comprises at least one SERS signal analysis unit.

12. A detection device according to claim 11 , wherein said at least one SERS detection unit sends said at least one display unit said signal analysis.

13. A detection device according to any one of the preceding claims, capable of detecting residues of at least one type of pesticide.

14. A detection device according to claim 13, wherein said at least one type of pesticide is selected from Fenthion, Cypermethrin, Acetamiprid and any combinations thereof.

15. A detection device according to claims 13 or 14, wherein said at least one type of pesticide is detected at levels below 1 mg/L.

16. A detection device according to any one of claims 13 to 15, wherein said at least one type of pesticide is detected on a surface of a food item.

17. A detection device comprising:

(a) at least one sample collection and preparation unit;

(b) at least one SERS tape unit;

(c) at least one spectrometer detection unit;

(d) at least one display unit;

wherein all units are configured in a single automated device; and wherein said device is adapted for detecting at least one of a pesticide, a herbicide, a fertilizer, a food contaminant or any combination thereof, in a single sample collected.

18. A detection device according to claim 17, wherein said at least one SERS tape unit comprises at least one flexible tape.

19. A detection device according to claim 17, wherein said device further comprises at least one wetting unit comprising at least one organic solvent.

20. A detection device according to claim 19, wherein said at least one wetting unit further comprises water.

21. A detection device according to claim 19, wherein said at least one wetting unit is located before said at least one sample collection and preparation unit.

22. A detection device according to claim 19, wherein said at least one wetting unit is located after said at least one sample collection and preparation unit.

23. A detection device according to claim 17, further comprising at least one drying unit.

24. A detection device according to claim 17, wherein said at least one SERS detection unit comprises at least one SERS spectrophotometer.

25. A detection device according to claim 17, wherein said at least one SERS detection unit further comprises at least one SERS signal analysis unit.

26. A detection device according to claim 25, wherein said at least one SERS detection unit sends said at least one display unit said signal analysis.

27. A detection device according to claim 17, capable of detecting residues of at least one type of pesticide.

28. A detection device according to claim 17, capable of detecting residues of at least one type of food contaminant.

29. A detection device according to claim 27, wherein said at least one type of pesticide is selected from Fenthion, Cypermethrin, Acetamiprid and any combinations thereof.

30. A detection device according to claim 27, wherein said at least one type of pesticide is detected at levels below 1 mg/L.

31. A detection device according to any one of the preceding claims capable of detecting at least two food contaminants from a single sample of an object examined.

32. A detection device according to any one of the preceding claims capable of detecting at least three food contaminants from a single sample of an object examined.

33. A detection device according to any one of the preceding claims capable of detecting at least four food contaminants from a single sample of an object examined.