NANOTECHNOLOGY AND BIOSENSORS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0227790
• Multistate No.: NC-_old1194
• Project Start Date: Dec 1, 2011
• Project End Date: Sep 30, 2016
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIVERSITY OF MISSOURI
(N/A)
COLUMBIA,MO 65211

Performing Department
Food Systems & Bioengineering

Non Technical Summary
This multidisciplinary project involves using nanotechnology and biosensors to address food safety problems with the aid of some of the latest developments in nanotechnology. New technologies were developed for characterizing nanoscale processes and to fabricate self-assembled nanostructures. SERS method coupled with nanostructures offers an alternative for increasing sample throughput at reduced per sample cost. SERS is a rapid, simple, ultrasensitive, and powerful analytical technique which provides qualitative and quantitative information on trace amounts of food contaminants. Having cost-efficient technologies to quickly and accurately screen foods would be a valuable tool for the US food safety inspectors and the food industry to improve inspection by providing increased capacity for screening a larger number of foods. The results of this project will serve the consumer demand for safe and wholesome foods and increase public confidence in our food supply. In addition, a framework was established for assessing environmental and health risks for nanotechnologies applied to food, agriculture and biological systems.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
711	5010	2000	100%

Knowledge Area
711 - Ensure Food Products Free of Harmful Chemicals, Including Residues from Agricultural and Other Sources;

Subject Of Investigation
5010 - Food;

Field Of Science
2000 - Chemistry;

Keywords

food safety

sers

rapid detection

contaminants

Goals / Objectives
Develop new technologies for characterizing fundamental nanoscale processes Construct and characterize self-assembled nanostructures Develop devices and systems incorporating microfabrication and nanotechnology Develop a framework for economic, environmental and health risk assessment for nanotechnologies applied to food, agriculture and biological systems Produce education and outreach materials on nanofabrication, sensing, systems integration and application risk assessment

Project Methods
(1) We used several new technologies including CVD, solution-based crystal growth, and spin coating methods to fabricate SERS-active nanosubstrates. The purpose was to develop a variety of nanosubstrates, test their performance, screen and identify best substrates that show reliable and consistent performance and are suitable for large scale fabrication. CVD is a microfabrication technique used to deposit thin films on wafers. A typical CVD is conducted under vacuum and elevated temperatures (on a heating stage). Thin films (such as Si, SiO2, SiC, etc) and various nanomaterials could uniformly grow on the wafer substrate. Solution-based crystal growth method was also used to prepare uniform ZnO nanostructures. (2) We synthesized Au and Ag based nanoparticles, aggregates, and dendrites, and optimize the protocol to improve structural uniformity. Metallic nanoparticles were prepared by a generic chemical reduction method in solution. Different sizes and shapes of nanoparticles were obtained by controlling the reaction temperature, the concentration of precursor solution, the type of reducing agent, and the presence of surfactants as a shaping template. The resulting metallic aggregate were physically stable and optically active. (3) Microfabrication and nanotechnology were used in this study to develop devices and systems. Spin coating was used to apply uniform thin films to flat substrates. An excess amount of a solution was placed on a substrate, which was then rotated at a high speed in order to spread the fluid by centrifugal force. When nanomaterials are mixed with the solution, a uniform coating with nanostructures was deposited on wafers. Both CVD and spin coating are microfabrication techniques suitable for making nanostructures in large scale, and these two methods were used in our proposed work. (4) We developed a framework and strategies to better assess economic, environmental and health risks for applying nanotechnologies and nanomaterials to food, agriculture and biological systems. We studied the effects of engineered nanoparticles (silver, ZnO) on gut natural microflora, and studied their toxicity using cell cultures such as Caco-2 cell line.

Progress 12/01/11 to 09/30/16

Outputs
Target Audience:The target audiences include people from the food industry, academia (faculty and students, etc), the science community, and the government agencies. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided training for three doctoral students and three Master's students. How have the results been disseminated to communities of interest?We have disseminated the results to the industry and scientific communities at professional conferences such as IFT, ACS, IBE, and IAFP. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? In this project, we used new technologies to develop nanostructures and nanosubstrates for surface-enhanced Raman spectroscopy (SERS) applications. The SERS method was evaluated for detection and characterization of biological and chemical contaminants in food products. Research accomplishments include: 1) Development and use of gold nanoprobes coupled with superparamagnetic beads for rapid detection of aflatoxin M1 in milk by dynamic light scattering; 2) Facile synthesis of Au-Ag core-shell nanoparticles with uniform sub-2.5 nm interior nanogaps for SERS applications; 3) Detection of pesticides and herbicides in foods and drinking water by SERS coupled with gold nanostructures. We have developed a variety of novel nanostructures using gold, silver, and other materials and studied their applications in food safety, specifically for rapid detection of chemical and biological contaminants in food matrices. A simple two-step method was developed to create standing gold nanorod arrays using gold nanorods with aspect ratio of 2.0 as building blocks. Results show that nearly all the nanorods (~95%) were vertically aligned on the silicon surface except a very small amount of nanorods near the pinned edge. Standing gold nanorod arrays were also created by the two-step method using gold nanorods with a higher aspect ratio (~3.4). These standing gold nanorod arrays were used in rapid detection of chemical food contaminants such as pesticides. We developed a rapid and simple method to functionalize gold nanorods by polyethylene glycol (PEG). PEG was successfully loaded on the CTAB-protected gold nanorods in 30 min using Tris buffer with pH of 3.0. The result shows that the PEG-modified gold nanorods could sustain the 1.0 M of NaCl while CTAB-protected gold nanorods aggregated immediately after the addition of NaCl. Compared to a traditional 24-h method in CTAB/carbonate solution, the proposed method has a higher loading speed and a higher coverage density of PEG on gold nanorods. We studied the consumer and food products sold on the market that contain various engineered nanomaterials such as silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs). We developed a novel, simple, rapid, and accurate method to detect AgNPs and AuNPs in consumer products using SERS coupled with an effective Raman indicator aminothiophenol (pATP). SERS measurement was conducted to detect AgNPs and AuNPs using pATP as an indicator. The pATP can strongly bind onto nanoparticles, generating enhance Raman signals that can be used for measurement. The results demonstrate that SERS measurement can be an effective method for detection of ENMs, and it can easily distinguish AgNPs and AuNPs from other non-nanoparticle species in the complex matrices.

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: Liu, B., Zhou, P., Liu, X.M., Sun, X., Li, H., Lin, M. 2013. Detection of pesticides in fruits by surface-enhanced Raman spectroscopy coupled with gold nanostructures. Food Bioprocess Tech. 6(3), 710-718.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Zhang, Z., Lin, M., Zhang, S., Vardhanabhuti, B. 2013. Detection of aflatoxin M1 in milk by dynamic light scattering coupled with superparamagnetic beads and gold nanoprobes. J. Agric. Food Chem. 61(19), 4520-4525.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Zhang, Z., Lin, M. 2014. High-yield preparation of vertically aligned gold nanorod arrays via controlled evaporation-induced self-assembly method. J. Mater. Chem. C. 2 (23), 4545-4551.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Nguyen, T., Zhang, Z., Mustapha, A., Li, H., Lin, M. 2014. Use of graphene and gold nanorods as substrates for detection of pesticides by surface enhanced Raman spectroscopy. J. Agric. Food Chem. 62(43), 1044510451.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Zhang, Z., Yu, Q., Li, H., Mustapha, A., Lin, M. 2015. Standing gold nanorod arrays as reproducible SERS substrates for measurement of pesticides in apple juice and vegetables. J. Food Sci. 80(2), N450-458.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Zhang, Z.; Lin, M. 2014. Fast loading of PEG-SH on CTAB-protected gold nanorod. RSC Adv. 4(34), 17760-17767.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Zhang, Z.; Zhang, S.; Lin, M. 2014. DNA-embedded Au-Ag core-shell nanoparticles assembled on silicon slides as a reliable SERS substrate. Analyst 139(9), 2207-2213.
• Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Fan, C., Lin, M. The use of surface enhanced Raman spectroscopy to differentiate E. coli O157:H7 from other bacteria inoculated into apple juice. 2012 IFT Annual Meeting. Las Vegas, NV. June 24-28, 2012.
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Zhong, Z.; Wang, P.; Lin, M. 2014. Competitive effect in surface enhanced Raman spectroscopy (SERS) detection of food contaminants. 2014 IFT Annual Meeting. New Orleans, LA. June 21-24, 2014.
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Nguyen, T. H.D.; Zhang, Z.; Mustapha, A.; Li H.; Lin, M. 2015. Use of graphene and gold nanorods as substrates for detection of pesticides by surface enhanced Raman spectroscopy. 2015 IFT Annual Meeting. Chicago, IL. July 11-14, 2015.
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Lin, M. 2015. The Use of Standing gold nanorod arrays as reproducible SERS substrates for the detection of pesticides in foods. 2015 Institute of Biological Engineering (IBE) annual meeting. St. Louis, MO, March 5-7, 2015.

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:The target audiences include people from the food industry, academia (faculty and students), the science community, and the government agencies. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided training for several doctoral students and Master's students. How have the results been disseminated to communities of interest?The results of this project were presented at the IFT, IAFP, IBE conferences. Audiences were from the academia, the food industry, and government. What do you plan to do during the next reporting period to accomplish the goals?In the next report period, we will continue to (1) develop and characterize self-assembled nanostructures; (2) develop devices and systems based on nanotechnology for use as nanosensors; and (3) provide risk assessment for nanotechnologies and nanomaterials used in food, agriculture, and biological systems.

Impacts
What was accomplished under these goals? During the reporting period, we aimed to study the consumer and food products sold on the market that contain various engineered nanomaterials (ENMs) such as silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs). These nanomaterials possess novel physical and chemical properties that can be used for wide applications in agriculture and food safety. However, current analytical methods to detect and measure ENMs are time-consuming, labor-intensive, and expensive. Therefore, the objective of this study was to develop a novel, simple, rapid, and accurate method to detect AgNPs and AuNPs in consumer products using surface-enhanced Raman spectroscopy (SERS) coupled with an effective Raman indicator aminothiophenol (pATP). SERS measurement was conducted to detect AgNPs and AuNPs using pATP as an indicator. The pATP can strongly bind onto nanoparticles, generating enhance Raman signals that can be used for measurement. In this study, the pATP was combined with Ag/Au stock solution, AgNO3, AgNPs-citrate coating, AuNPs-citrate coating, AuCl, AgNPs, AuNPs, and five commercial products: Silver Throat Spray, Silver Dietary Supplement, Rejuvenating A Therapy Serum, Instant Wrinkle Filling Capsules, and Colloidal Gold Natural Supplement to study the differences in SERS spectral data. The observed spectra of AgNPs and AuNPs have similar peaks at ~390, ~1087, and ~1590 cm-1 that can be attributed to the C-S stretching vibration, C-C stretching vibration, and C-H stretching vibration, respectively. The results demonstrate that SERS measurement can be an effective method for detection of ENMs, and it can easily distinguish AgNPs and AuNPs from other non-nanoparticle species in the complex matrices.

Publications

• Type: Journal Articles Status: Published Year Published: 2014 Citation: Zhang, Z.; Lin, M. 2014. High-yield preparation of vertically aligned gold nanorod arrays via controlled evaporation-induced self-assembly method. J. Mater. Chem. C. 2,4545-4551
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Nguyen, T.; Zhang, Z.; Mustapha, A.; Li, H.; Lin, M. 2014. Use of graphene and gold nanorods as substrates for detection of pesticides by surface enhanced Raman spectroscopy. J. Agric. Food Chem. 62(43),1044510451.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Song, X., Li, H., Hu, Z.Q., Mustapha, A., Lin, M. 2014. Characterization and quantification of engineered nanoparticles in food by epithermal instrumental neutron activation analysis and electron microscopy. J. Food Measurement & Characterization. 8(3),207-212.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Zhang, Z.; Yu, Q.; Li, H.; Mustapha, A.; Lin, M. 2015. Standing gold nanorod arrays as reproducible SERS substrates for measurement of pesticides in apple juice and vegetables. J. Food. Sci. 80(2), N450-458.
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Lin, M. 2015. The Use of Standing gold nanorod arrays as reproducible SERS substrates for the detection of pesticides in foods. 2015 Institute of Biological Engineering (IBE) annual meeting. St. Louis, MO, March 5-7, 2015.
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Nguyen, T. H.D.; Zhang, Z.; Mustapha, A.; Li H.; Lin, M. 2015. Use of graphene and gold nanorods as substrates for detection of pesticides by surface enhanced Raman spectroscopy. 2015 IFT Annual Meeting. Chicago, IL. July 11-14, 2015.

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: The food industry and the science community. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? This project has provided training for several doctoral students and Master's students. How have the results been disseminated to communities of interest? The results of this project were presented at the IFT, IAFPmeeting. Audiences were from academia, the food industry, and government. What do you plan to do during the next reporting period to accomplish the goals? In the next report period, we will continue to (1) develop and characterize self-assembled nanostructures; (2) develop devices and systems based on nanotechnology for use as nanosensors; and (3) provide risk assessment for nanotechnologies and nanomaterials used in food, agriculture, and biological systems.

Impacts
What was accomplished under these goals? We developed a rapid and simple method to functionalize gold nanorods by polyethylene glycol (PEG) that can be used for plasmonic sensing and other applications. PEG was successfully loaded on the CTAB-protected gold nanorods in 30 min using Tris buffer with pH of 3.0. On the contrary, the functionalization of gold nanorods in water induced the aggregation of gold nanorods and produced a floating layer of randomly aggregated nanorods at the water-air interface. The concentration of mPEG-SH has no significant influence on the optical property of gold nanorods modified by the proposed method. The result shows that the PEG-modified gold nanorods could sustain the 1.0 M of NaCl while CTAB-protected gold nanorods aggregated immediately after the addition of NaCl. Compared to a traditional 24-h method in CTAB/carbonate solution, the proposed method offers a higher loading speed and a higher coverage density of PEG on gold nanorods. It was also found that the PEG-modified NR-610 could form a very uniform monolayer on silicon upon the slow evaporation of water content. This method might open a new route to fabricate substrates for bio-medication, detection of food contaminants, and environmental monitoring.

Publications

• Type: Journal Articles Status: Published Year Published: 2014 Citation: Zhang, Z., Zhang S., Lin, M.* 2014. DNA-embedded Au-Ag core-shell nanoparticles assembled on silicon slides as a reliable SERS substrate. Analyst 139(9), 2207-2213.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Zhang, Z., Lin, M.* 2014. Fast loading of PEG-SH on CTAB-protected gold nanorod. RSC Adv. 4 (34), 17760-17767.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Zhang, Z., Lin, M.* 2014. High-yield preparation of vertically aligned gold nanorod arrays via controlled evaporation-induced self-assembly method. J. Mater. Chem. C. 2 (23), 4545-4551.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Yada*, R.Y., Buck, N., Canady, R., DeMerlis, C., Duncan, T., Janer, G., Juneja, L., Lin, M., McClements, J., Noonan, G., Oxley, J., Sabliov, C., Tsytsikova, L., Yourick, J., Zhong, Q., Thurmond, S. 2014. Engineered nanoscale food ingredients: evaluation of current knowledge on material characteristics relevant to uptake from the gastrointestinal tract. Compr. Rev. Food Sci. Food Saf. 13(4):730744.

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: The food industry and science community. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? This project has provided training for several doctoral students and Master's students. How have the results been disseminated to communities of interest? The results of this project were presented at the IFT meeting. Audiences were from academia, the food industry, and government. What do you plan to do during the next reporting period to accomplish the goals? During the next report period, we will continue to (1) develop new technologies for characterizing fundamental nanoscale processes; (2) construct and characterize self-assembled nanostructures; (3) develop devices and systems based on nanotechnology for use as nanosensors; and (4) provide risk assessment for nanotechnologies and nanomaterials applied to food, agriculture, and biological systems.

Impacts
What was accomplished under these goals? (1) A facile method was established to fabricate uniform nanogaps between Au core and Au/Ag alloy shell. The size of nanogaps is controllable due to fast dissolution of AgCl and AgBr in CTAB and the crystal growth of shell on designed template. These Au/Ag core/shell nanoparticles with uniform sub-2.5 nm interior nanogaps can be potentially used for various applications. (2) The contamination of Ag NPs in pears was detected, characterized, and quantified by a combination of techniques, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and inductively coupled plasma optical emission spectrometry (ICP-OES). Pear samples were treated with two different sizes (20 and 70 nm in diameter) of Ag NPs and stored for different times. The results demonstrate that a combination of techniques could provide accurate results for detection, characterization, and quantification of engineered nanoparticles in agricultural products. (3) We developed a rapid and sensitive method for detection of aflatoxin M1 (AFM) by dynamic light scattering (DLS) coupled with superparamagnetic beads and gold nanoprobes. Magnetic beads-based immunosorbent assay (MBISA) was used to measure the concentration of AFM by direct competition between AFM and nanoprobes. Compared to conventional ELISA, MBISA could effectively reduce the incubation time to 15 min in buffer solution and completely eliminate the color development step, thus simplifying the analysis of AFM. These results demonstrate that DLS coupled with magnetic beads and gold nanoprobes is a rapid and effective method to detect AFM. This method could also be easily extended to rapid detection of other mycotoxins and biological species. (4) In this study, we used surface-enhanced Raman spectroscopy (SERS) coupled with SERS-active gold substrates to detect trace amount of pesticides widely used in strawberry plants, including captan, myclobutanil, and pyraclostrobin.

Publications

• Type: Journal Articles Status: Awaiting Publication Year Published: 2013 Citation: Song, X.; Li, R.; Li, H.; Hu, Z.Q.; Mustapha, A.; Lin, M. 2013. Characterization and quantification of zinc oxide and titanium dioxide nanoparticles in foods. Food and Bioprocess Technology. Published online.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Zhang, Z.; Lin, M.; Zhang, S.; Vardhanabhuti, B. 2013. Detection of aflatoxin M1 in milk by dynamic light scattering coupled with superparamagnetic beads and gold nanoprobes. J. Agric. Food Chem. 61(19), 45204525.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Song, X.; Li, H.; Al-Qadiri, H.M.; Lin, M.* 2013. Detection of herbicides in drinking water by surface-enhanced Raman spectroscopy coupled with gold nanostructures. Journal of Food Measurement & Characterization. 7(3), 107-113.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Zhang, Z.; Zhang, S.; Lin, M. 2013. Facile synthesis of Au-Ag core-shell nanoparticles with uniform sub-2.5 nm interior nanogaps. Chemical Communications. 49(76), 8519-8521.

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: Outputs during the reporting period include: the study about using a nanotechnology-based sensing and detection technique, surface-enhanced Raman spectroscopy (SERS), to detect and characterize pesticides extracted from fruit surfaces. In this study, gold-coated SERS-active nanosubstrates were used for SERS measurement. Three types of pesticides (carbaryl, phosmet, and azinphos-methyl) widely used in apples and tomatoes were selected. Significantly enhanced Raman signals of pesticides were acquired by SERS from the extract of fruit samples and exhibited characteristic patterns of the analytes. Multivariate statistical methods such as partial least squares (PLS) and principal component analysis (PCA) were used to develop quantitative and qualitative models for detection. SERS was able to detect all three types of pesticides extracted from fruit samples at the ppm level. The study of detection limit demonstrate that at 99.86% confidence interval, SERS can detect carbaryl at 4.51 ppm, phosmet at 6.51 ppm, and azinphos-methyl at 6.66 ppm spiked on apples; and carbaryl at 5.35 ppm, phosmet at 2.91 ppm, and azinphos-methyl at 2.94 ppm on tomatoes. Most of these detection limits meet the maximum residue limits established by FAO/WHO. Satisfactory recoveries (78 to 124%) were achieved for samples with concentrations at and larger than the detection limit. PARTICIPANTS: This project has provided training for several doctoral students and Master's students. TARGET AUDIENCES: The results of this project were presented at the IFT meeting. Audiences were from academia, the food industry, and government. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Outcomes and impacts of the study include the scientific data and findings that can help address a growing concern in recent years for consumers about contamination of pesticides in fruits due to increasing use of pesticides in agriculture. Today's food safety situation calls for development of rapid, sensitive, and reliable methods that are suitable for on-site detection of food contaminants. Compared with other methods such as chromatogrphy-based techniques, SERS has the following advantages to meet such requirements: simplicity of sample preparation, acceptable accuracy and reliability, and wide applications. In addition, more effective yet simple extraction techniques and better performing substrates will greatly improve the capability of SERS methods. These results demonstrate that SERS coupled with novel SERS-active nanosubstrates is a rapid, sensitive, and reliable method for detection and characterization of chemical contaminants in foods.

Publications

• Liu, B., Zhou, P., Liu, X.M., Sun, X., Li, H., Lin, M.* 2012. Detection of pesticides in fruits by surface-enhanced Raman spectroscopy coupled with gold nanostructures. Food and Bioprocess Technology. In press.
• Fan, C., Hu, Z.Q., Mustapha, A., Lin, M. 2011. Rapid detection of food- and waterborne bacteria using surface enhanced Raman spectroscopy coupled with silver nanosubstrates. Applied Microbiology and Biotechnology. 92:1053-1061.
• Zhang, Z.; Kong, F.; Vardhanabhuti, B.; Mustapha, A.; Lin, M. 2012. Detection of engineered silver nanoparticle contamination in pears. J. Agric. Food Chem. In press.