Source: UNIV OF MASSACHUSETTS submitted to
INVESTIGATE THE INTERACTIONS BETWEEN SILVER NANOPARTICLES AND LEAFY VEGETABLES US
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1005479
Grant No.
2015-67017-23070
Project No.
MASW-2014-05697
Proposal No.
2014-05697
Multistate No.
(N/A)
Program Code
A1331
Project Start Date
Feb 1, 2015
Project End Date
Jan 31, 2019
Grant Year
2015
Project Director
He, L.
Recipient Organization
UNIV OF MASSACHUSETTS
(N/A)
AMHERST,MA 01003
Performing Department
Food Science
Non Technical Summary
Silver nanoparticles (AgNPs) have wide applications due to their unique antibacterial activities and physicochemical properties, however, many studies showed their potential toxicity to human health. AgNPs from pesticides and industrial materials can possibly contaminate fresh produce through surface contamination and root uptake. However, knowledge on the physical and molecular mechanisms of AgNPs contaminating fresh produce and their fates is currently limited. The overall goal is to investigate the interactions between AgNPs and leafy vegetables (i.e. spinach and lettuce) using surface-enhanced Raman spectroscopic (SERS) mapping. SERS is a special technique that can provide the true information of the metallic AgNPs (not ions) on and in plant tissues. In addition, molecular information about the plant components adsorbed onto those NPs can be characterized. We will investigate AgNPs attachment on and penetration into leaves via surface spray, and evaluate the impact of postharvest washing on surface attached AgNPs. We will also investigate AgNPs distribution in plant tissues and their fates via root-to-shoot exposure. Two growth models, a hydroponic and a soil system will be used. The successful completion of this study will help us to have a better understanding on how AgNPs would possibly contaminate fresh produce such as spinach and lettuce. Understanding these processes will help us to evaluate the risk level of the AgNP contamination in fresh produce and develop a better control strategy to prevent contamination, which is important to maintain the safety and sustainability of agriculture and food system.
Animal Health Component
0%
Research Effort Categories
Basic
40%
Applied
30%
Developmental
30%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
31414992000100%
Knowledge Area
314 - Toxic Chemicals, Poisonous Plants, Naturally Occurring Toxins, and Other Hazards Affecting Animals;

Subject Of Investigation
1499 - Vegetables, general/other;

Field Of Science
2000 - Chemistry;
Goals / Objectives
Overall GoalThe overall goal of this proposal is to investigate the interactions between AgNPs and leafy vegetables using SERS mapping to understand the physical and molecular mechanisms AgNPs contaminating fresh produce. This is important for the long-term goal of maintaining the safety and sustainability of agriculture and food system.Objectives are:1. Preparation and characterization of AgNPs with different sizes, shapes, and surface modifications.2. In vitro characterization of plant biomolecules on AgNPs using SERS.3. Identification, quantification, and characterization of AgNPs attachment on and penetration into leaves via surface spray using SERS mapping.4. Identification, quantification, and characterization of AgNPs distribution in plant tissues and their fate via root-to-shoot exposure using SERS mapping.
Project Methods
In the proposed study, AgNPs with different sizes, shapes, and surface modifications will be prepared and characterized. Major plant biomolecules such as chlorophyll, cellulose, lipids, proteins, and nucleic acids will be either extracted from plants or purchased. Their interactions with the AgNPs will be characterized by SERS in vitro, which can serve as references for the in vivo study. Two leafy vegetables (spinach and lettuce) will be used as the model plants because they are highly associated with the other food safety problem, i.e. food pathogens. Two contamination routes, surface spray and root-to-shoot exposure will be applied for studying NP attachment and internalization. For studying NP attachment and penetration, surface spray of AgNPs will be applied to mimic the situations of spraying NP containing pesticides or irrigating NP contaminated water. SERS mapping will be used to quantify and characterize the NPs on and in leaves. We will also evaluate the impact of postharvest washing on surface attached AgNPs. For studying NP internalization and fate, we will use the root-to-shoot exposure in a hydroponic system and a soil system. SERS mapping will be used to quantify and characterize the NPs on roots and in leaves. Results will be validated using HRTEM for observing mineral lattice and TEM coupled with electron diffraction for identifying mineral phase. Results from AgNPs with different sizes, shapes, and surface modifications, as well as two plants in two growing systems will be statistically compared.

Progress 02/01/15 to 01/31/19

Outputs
Target Audience:government decision makers and scientists who want to have a better understanding of how AgNPs would possibly contaminate fresh produce such as spinach and lettuce. Understanding these processes will help us to evaluate the risk level of the AgNP contamination in fresh produce and develop a better control strategy to prevent contamination, which is important to maintain the safety and sustainability of agriculture and food system. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?In total, we trained 5 graduate students, 2 postdocs, 2 undergraduates through the project. How have the results been disseminated to communities of interest?We published total of 13 papers and presented at more than 10 conferences during this project. We also did a Raman/SERS short course that was open to the public to teach some basics of Raman/SERS and their applications in studying chemistry, microbes and engineered nanomaterials in environmental, agriculture and food matrices. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? 1. We developed several effective and rapid methods to detectAgNPs in environmental water matricesand on/in plant tissues in situ as well as after extraction. 2. We gained knowledge of how AgNPs interacted with plant leaves and roots and their biological fates. 3. We developed an effective method to remove AgNPs attached on the edible leaf surfaces.

Publications

  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Guo, Huiyuan, Chuanxin Ma, Lauren Thistle, My Huynh, Chenghao Yu, Daniel Clasby, Benny Chefetz et al. "Transformation of Ag ions to Ag nanoparticles-loaded AgCl microcubes in the plant root zone." Environmental Science: Nano (2019).6, 1099 - 1110
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Zhang, Zhiyun, Huiyuan Guo, Chuanxin Ma, Ming Xia, Jason C. White, Baoshan Xing, and Lili He*. "Rapid and efficient removal of silver nanoparticles from plant surfaces using sodium hypochlorite and ammonium hydroxide solution." Food Control 98 (2019): 68-73.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Guo, Huiyuan, Leigh C. Hamlet, Lili He*, and Baoshan Xing*. "A field-deployable surface-enhanced Raman scattering (SERS) method for sensitive analysis of silver nanoparticles in environmental waters." Science of The Total Environment 653 (2019): 1034-1041.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Zhao, Bin, Tianxi Yang, Zhiyun Zhang, Michael E. Hickey, and Lili He*. "A Triple Functional Approach To Simultaneously Determine the Type, Concentration, and Size of Titanium Dioxide Particles." Environmental science & technology 52, no. 5 (2018): 2863-2869.


Progress 02/01/17 to 01/31/18

Outputs
Target Audience:government decision makers and scientists who want to have a better understanding of how AgNPswould possibly contaminate fresh produce such as spinach and lettuce. Understanding these processes will help us toevaluate therisk level of the AgNP contamination in fresh produce and develop a better control strategy to prevent contamination, whichis important to maintain the safety and sustainability of agriculture and food system. Changes/Problems:we requested a no cost extensiondue to the unexpected contamination happened in the green house, so we need to re-grow the spinach for the project. What opportunities for training and professional development has the project provided?We trained two graduate students, one undergraduate students during this project. How have the results been disseminated to communities of interest?We published 2 papers and presented in multiple conferences. What do you plan to do during the next reporting period to accomplish the goals?We will further evaluate the new extraction method and combined this method with the new washing method to quantify the amount of AgNPs penetrated into the plant leaves we will also study the AgNP translocation in live plants

Impacts
What was accomplished under these goals? 1.We developed a more effective washing method to remove surface AgNP residues from fresh produce using lorox bleach (200 mg/L, 5 min), ammonium hydroxide solution (NH3·H2O, 1 min), and finally rinsed by deionized water (DI Water, 1 min). After this washing, we can remove over 90% of Ag residuals from these AgNPs contaminated spinach leaves. 2. We developed a more effective extracting method for detecting AgNPs in plant leaves. This method uses4-Mercaptobenzoic acid (4-MBA) in acetone and methanol mixed solution to digest the plant leaves. Then a mixture of water, ethyl acetate, and hexane are added into the digesta to extracthe 4-MBA modified AgNPs into the layer of hexane and ethyl acetate based on the difference of polarity. The AgNPs contained solvents are then filtered through a filter membrane to collect AgNPs for SERS measurement. In this way, we can detect trace amount of AgNPs in plant leaves within 2 hours. 3. We studied the bioformation of AgNPs by plant root systems asaffected by various conditions. We found theCl- in plant root exudatesplays an important role in initiating the AgNP formation through the reducing electrons produced by AgCl NPs under light exposure and high MW molecules (e.g., proteins and polysaccharides) are responsible for the stabilization of the formed AgCl NPs and AgNPs.

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Huiyuan Guo, Lili He*, Baoshan Xing*. Applications of Surface-Enhanced Raman Spectroscopy on Nanoparticle Analysis in the Environment. Environmental Science: Nano, 2017, DOI: 10.1039/C7EN00653E.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Yanqi Qiu, Chen Tan, Zhiyun Zhang, Lili He*. A facile solvent mediated self-assembly silver nanoparticle mirror substrate for quantitatively improved surface enhanced Raman scattering. Analyst, 2017, DOI: 10.1039/C7AN00784A
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Huiyuan Guo, Feng Han, Lili He, Baoshan Xing. New insight into naturally occurring metal nanoparticles: role of plant root exudates. 2017 Sustainable Nanotechnology Organization Conference, Los Angeles, CA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Huiyuan Guo, Lili He, and Baoshan Xing. Conversion of silver ions to silver-containing particles exogenously by live plant roots grown under different nutritional conditions. The 14th International Phytotechnology Conference, Montreal, Canada. September 25-29, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Huiyuan Guo, Lili He, and Baoshan Xing. Bioformation of silver nanoparticles by plant root systems as affected by growth conditions. The 253rd American Chemical Society National Meeting & Exposition. San Francisco, CA. April 2-6, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Leigh C. Hamlet, Huiyuan Guo, Lili He, Baoshan Xing. 2017. Development of a surface-enhanced Raman scattering (SERS) method for fieldable and sensitive detection of silver nanoparticles in environmental waters. 2017 Sustainable Nanotechnology Organization Conference, Los Angeles, CA.


Progress 02/01/16 to 01/31/17

Outputs
Target Audience:Target audiences: government decision makers and scientists who want to have a better understanding of how AgNPs would possibly contaminate fresh produce such as spinach and lettuce. Understanding these processes will help us to evaluate the risk level of the AgNP contamination in fresh produce and develop a better control strategy to prevent contamination, which is important to maintain the safety and sustainability of agriculture and food system. Changes/Problems:Dr. Sam Nugen had moved to Cornell University, so he is no longer involved in this project. What opportunities for training and professional development has the project provided?We trained two graduate students, two undergraduate students, and one postdoc during this project. How have the results been disseminated to communities of interest?We published 5 papers, and presented in multiple seminars, conferences, and meetings. We also submitted one patent application. What do you plan to do during the next reporting period to accomplish the goals?1. We will furhter optimize and validate the method for extracting and detecting AgNPs in complex matrices. 2. We will evaluate the AgNP penetration and translocation on live plants 3. We will develop a more effective washing method to remove surface AgNP residue from fresh produce.

Impacts
What was accomplished under these goals? 1.improved the methodology We haveevaluated the interference of various ions, proteins and pigments (i.e. chlorophylls and carotenes extracted from spinach leaves) to the ferbam-based SERS method, and proved that the method could work in various matrices.We alsointegrated the syringe filter to the method which pushed the limit of detection to 5 ppb for detecting AgNPs in water. To improve the sensitivity of detection in complex matrices, we developeda method involvinginnovative triple-functional surfactant ligands produced from 4-mercaptobenzoic acid (4-MBA) and Tetraoctylammonium bromide (TOAB) to modify the hydrophobicity of the AgNPs and faciliate the extraction and detection. Using this method, we can detect 0.1 ppb AgNPs in water. 2. detected AuNP penetration into spinach leaves we used a non-destructive and label-free approach based on surface enhanced Raman spectroscopic (SERS) mapping technique to qualitatively detect and characterize gold nanoparticles (Au NPs), on and in spinach leaves in situ. We were able to detect the clearly enhanced signals from Au NPs at 15 to 125 nm on and in spinach leaves. Peak characterizations revealed the aggregation status of Au NPs and their interactions with plant biomolecules, such as chlorophylls and carotenoids. The developed approach will open a new analytical platform for various researches on studying ENPs' adhesion and accumulation. 3. determined the postharvest washing on Ag NPs removal from spinach leaves We evaluated the postharvest washing efficiency of several treatments, including deionized water, Tsunami® 100 and Clorox® bleach, on AgNPs removal from spinach leaves. Large amounts of AgNPs residues were still present on the leaf surface after rinsing with deionized water. The oxidizing agents of Tsunami® 100 (80 mg L-1) and Clorox® bleach (200 mg L-1) partly oxidized AgNPs and subsequently released Ag+ ions. This resulted in reductions in AgNPs presence; 16% for Tsunami® (although not statistically significant) but nearly 90% for Clorox® with SERS analysis. However, with regard to total Ag presence as measured by ICP-MS, there was no obvious difference between the two treatments. This can be explained by the fact that released Ag+ ions reacted with free chloride anions in Clorox® bleach and resulted in the formation AgCl particles (average size 162 ± 51 nm) on the spinach leaves. Due to the fact that AgCl is still potentially toxic to humans, as well as still having the potential to be further oxidized to ions or reduced to NP form, a significant safety concern remains. Future research will focus on the development of a safe, effective, and practice washing protocol for removing AgNPs from fresh produce surfaces. Additional work will address the issue of AgNPs penetration, and potential methods to alleviate the NP content under these circumstances.

Publications

  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Huiyuan Guo, Baoshan Xing* and Lili He*. 2016. Development of a filter-based method for detecting silver nanoparticles and their heteroaggregation in aqueous environments by surface-enhanced Raman spectroscopy. Environmental Pollution. 211, 198205.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Guo H, Xing B*, Hamlet LC, Chica A, He L*. Surface-enhanced Raman scattering detection of silver nanoparticles in environmental and biological samples. Science of The Total Environment. 2016;554:246-52.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Zhiyun Zhang, Huiyuan Guo, Yingping Deng, Baoshan Xing and Lili He*. Mapping gold nanoparticles on and in edible leaves in situ using surface enhanced Raman spectroscopy. RSC Advances. 2016. 2016. 6, 60152-60159.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Zhiyun Zhang, Huiyuan Guo, Thomas Carlisle, Arnab Mukherjee, Amanda Kinchla, Jason C. White, Baoshan Xing, and Lili He*. 2016. Evaluation of Postharvest Washing on Ag NPs Removal from Spinach Leaves. Journal of Agriculture and Food Chemistry. 64 (37), pp 69166922.
  • Type: Other Status: Other Year Published: 2016 Citation: Lili He. Invited talk. Development of Surface Enhanced Raman Spectroscopy for Food Safety applications. Stockbridge of Agriculture seminar. Feb.22. 2016
  • Type: Other Status: Other Year Published: 2016 Citation: Lili He. invited talk.  Development and applications of surface enhanced Raman spectroscopy in food safety. College of Chemistry and Chemical Engineering. Xiamen University. March, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Lili He. Invited talk.  Surface enhanced Raman Spectroscopy: one tool for all food contaminants. ACS C&EN Talented 12 symposium. Aug 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Huigyuan Guo, Baoshan Xing, and Lili He. Formation of Silver Nanoparticles by live plant root systems: mechanism and implication to plant toxicity. 13th international phytotechnologies conference, Hangzhou, China. Sept 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Zhiyun Zhang and Lili He. In situ and real time investigation of silver nanoparticles and spinach leaves interaction using surface enhanced Raman spectroscopy. 13th international phytotechnologies conference, Hangzhou, China. Sept 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Zhiyun Zhang and Lili He. oral presentation. Evaluation of postharvest washing on Ag NPs removal from spinach leaves. ACS-AGFD international student symposium. Aug 2016
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Lili He. poster presentation. Evaluation of Postharvest Washing on Ag NPs Removal from Spinach Leaves. NIFA food safety PD meeting. July. 2016
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Huiyuan Guo, Baoshan Xing*, Jason C. White, Arnab Mukherjee and Lili He*. 2016. Ultra-sensitive Determination of Silver Nanoparticles by Surface-enhanced Raman Spectroscopy after Hydrophobization-Mediated Extraction. Analyst. 141, 5261-5264.


Progress 02/01/15 to 01/31/16

Outputs
Target Audience:Target audiences: government decision makers and scientists who want to have a better understanding of how AgNPs would possibly contaminate fresh produce such as spinach and lettuce. Understanding these processes will help us to evaluate the risk level of the AgNP contamination in fresh produce and develop a better control strategy to prevent contamination, which is important to maintain the safety and sustainability of agriculture and food system. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two undergraduate and two graduatestudentshave been involved and trained through this project How have the results been disseminated to communities of interest?we published one journal article, presented two conference talks, one seminar talk, and one poster Guo, Huiyuan; Zhang, Zhiyun; Xing, Baoshan; Mukherjee, Arnab; Musante, Craig; White, Jason; He, Lili. 2015. Analysis of Silver Nanoparticles in Antimicrobial Products Using Surface-Enhanced Raman Spectroscopy (SERS). Environmental Science & Technology. 49(7):4317-24. Huiyuan Guo, Baoshan Xing,Lili He.Oral presentation: "Probing silver nanoparticles in environmental and biological samples by surface-enhanced Raman spectroscopy (SERS)". ACS Boston. 2015. Lili He. invited talk."Development and Applications of Surface Enhanced Raman Spectroscopy in Food Science". Young Scientist Symposium. ACS Boston. 2015. Lili He. invited talk."Surface-enhanced Raman spectroscopy: the next generation analytical tool for detection and characterization of nanoparticle contaminants". Connecticut Agricultural Experiment Station. 2015. Zhiyun Zhang.poster "SERS detection and characterization of gold nanoparticles on and in spinach leaves". SNO conference, portaland. Nov. 2015 What do you plan to do during the next reporting period to accomplish the goals?we will test different sizes of silver nanoparticles (AgNPs) on and in two different plant leaves (spinach and lettuce). we will also evalute the effectiveness of produce washing sanitizers on removing the AgNPs from the plant leaf surfaces.

Impacts
What was accomplished under these goals? Engineered nanoparticles are considered as emerging environmental, agricultural and food contaminants due to their potential toxicity to environment and human health. However, there is no such a technique that can rapidly and reliably detect and characterize nanoparticles in complex matrices, especially for those unstable nanoparticles such as silver nanoparticles (AgNPs). The objective for this study is to develop a rapid method for the detection of AgNPs which can be found in some pesticides on and in edible plants (i.e. spinach leaves).Surface-enhanced Raman spectroscopy (SERS) was applied in detection of AgNPs on and in edible plants. Both label-free and label-assisted approaches were evaluated for the detection of AgNPs in spinach leaves. Results showSERS can rapidly and reliably detect AgNPs of various coatings and sizes, and discriminate them from silver ions, silver chloride, silver bulk particles. We developed a label-free SERS mapping method to detect AgNPs on and in spinach leaves in situ and non-invasively. The spectral information also revealed the molecular interaction between AgNPs and plant biochemicals. We also developed a label-assisted method, which utilized a pesticide ferbam that can bind on the AgNPs strongly to detect the presence of as low as 0.57 mg/L AgNPs in spinach leaves juice. We demonstrate the great potential of the developed SERS methods for monitoring and characterizing of AgNP contaminants in environmental and biological samples, which can facilitate the conduction of reliable and economic nanotoxicity studies (e.g. mechanism and survey).

Publications

  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Guo, Huiyuan; Zhang, Zhiyun; Xing, Baoshan; Mukherjee, Arnab; Musante, Craig; White, Jason; He, Lili. 2015. Analysis of Silver Nanoparticles in Antimicrobial Products Using Surface-Enhanced Raman Spectroscopy (SERS). Environmental Science & Technology. 49(7):4317-24.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Huiyuan Guo, Baoshan Xing, Lili He. Oral presentation: Probing silver nanoparticles in environmental and biological samples by surface-enhanced Raman spectroscopy (SERS). ACS Boston. Aug. 2015.
  • Type: Other Status: Other Year Published: 2015 Citation: invited talk. Lili He. Surface-enhanced Raman spectroscopy: the next generation analytical tool for detection and characterization of nanoparticle contaminants. Connecticut Agricultural Experiment Station in Nov. 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Zhiyun Zhang, Lili He. Poster presentation: SERS detection and characterization of gold nanoparticles on and in spinach leaves. Sustainable Nanotechnology Organization conference. Portland in Nov 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Lili He. Development and Applications of Surface Enhanced Raman Spectroscopy in Food Science. Young Scientist Symposium. ACS Boston. 2015.