Lab of Plant Food Safety and Quality
--Evaluation of Agro-chemicals to Secure Food Safety from Farm to Fork
This Lab is the core part of Jiangsu Key Laboratory of Food Quality and Safety-State Key Laboratory cultivation Base of MOST, Key Laboratory of Agric-product safety risk evaluation (Nanjing Lab, Ministry of Agriculture, China), Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture, China), Supervision and testing center for processed agro-product (Ministry of Agriculture, China), and Sino-American joined food safety research center (established with National Food safety and toxicology center, Michigan State University, USA, 2006). The lab conducts research of evaluation, detection and risk assessment of agro-chemicals and contaminations (low molecular weight) from farm to fork and particularly focuses on two areas: 1) bio-elements based rapid method development for agro-chemicals and contamination determination, 2) dissipation, reduction and risk assessment of agro-chemicals after application.
1) For the bio-elements based rapid detection method development, we have conducted and achieved several antibody based methods for different chemical detection. For example, using Diethylphosphono acetic acid (DPA) as hapten, which present the classic structure of organophosphorus pesticides, broad specificity polycolonal antibodies against a group of organophosphorus pesticides were generated ; and we also firstly reported the ELISA method for the new herbicide H-9201 detection . Phage displayed technology is one of the most effective way of selection and expression of scFvs, and also is a good preparation methods to obtain anti-idiotypic antibodies. Our team have constructed an immune phage display library for screening the higher affinity scFv against Ivermectin ; and using the same technology and Tomlinson I+J library successfully isolated scFvs specific to target antigens and established the indirect competitive ELISA (ic-ELISA) immunological analysis method for Avermectin, Cry1B and Cry1C toxins detection [4,5,6]. Meanwhile, by conducting a naïve mouse phage displayed library, anti-Cry1Ab scFvs were succeed . Using the purified anti-malathion antibody as immobilized antigen, we were successfully obtained Ab2-scFv of malathion from phage displayed library . Furthermore, using purified anti-Bt toxin antibody as antigen for the antibody library selection, seven positive clones (anti-idiotypic scFvs) were selected; and two of them were characterized with strong binding ability to the antibodies competed with Cry1Ab toxin. Further bioassay tests and pest’s receptor binding test confirmed that the subtypes of anti-idiotypic scFvs were “Ab2β” type and also presented insecticidal activity [manuscript in preparation]. We also purchase Oligonucleotide (nucleic acid) aptamer based method development for chemical recognization . Using modified-SELEX technology, several single stranded DNA aptamer were selected for the organophosphorus pesticides and acetamiprid binding [10,11]. Thereafter, with assistance of computational design and molecular docking and modeling, the molecular interactions were profiled and truncated to narrow down the binding region of target. Thereafter, a variant fused by minimum functional structures with increased broad specificity and affinity was achieved to a fluorescence polarization aptamer assay and employed in real sample test .
2) Study on the dissipation, reduction and risk assessment of agro-chemicals releasing to environment. Since 2006, our team has been authorized by ICAMA (The Institute for the Control of Agrochemicals, Ministry of Agriculture) to test and evaluate the consequence of agrochemicals to be used on crops and to provide essential data for agrochemicals. Since then, more than 50 pesticide active ingredients on 20 crops have been studied; about ten thousands data including the consequence of pesticide residue degradations and residues in products; and over 100 guidelines for safety application of pesticides have been published; and more than 20 Maximum Residue Limits have been proposed for the National Food Safety Standard. Up to now, methods for detections of approximately 500 pesticide active ingredients in different crops matrices by using HPLC-MS/MS have been developed. For example, The dissipation and residues of 2,4-D-dimethylammonium, profenofos in ecosystem have been profiled by LC/MS/MS[13,14]; and the dynamics and residue content of chlorpyrifos and dichlorvos in cucumber grown in greenhouse were investigated; the dissipation and environment fate of new herbicide H-9201 in environment was firstly studied and the most likely pathway of hydrolysis was outlined and identified by GC/MS . We also conducted study of dissipation of chlorpyrifos in rice, soil and water under paddy field conditions . Phytotoxicity and uptake of chlorpyrifos by Chinese cabbage and cabbage were studied in the laboratory condition, which revealed that the root length and fresh weight of Chinese cabbage were affected by chlorpyrifos in low concentration; however, cabbage was affected by chlorpyrifos in high concentration; both plants could uptake chemicals via roots delivery system . Thereafter, we investigated the effects of home preparation of raw agro-product, which revealed that storage, washing, detergent, and ultrasonic cleaning could cause reduction of the organophosphorus pesticides on agro-products; it is useful for reducing the dietary exposure ; washing with low concentration of limonene was also useful for the elimination of pesticide residues on vegetable, which also could avoid the second hand contamination compared with chemical detergent . For the agrochemicals, which could persistently present in soil after application, using charcoal for soil remediation has been studied, which could enhance the sorption of organic contaminants, such as diuron pesticide. Our study showed that the presence of small amounts of black carbon in the form of charcoals in soil can have a major effect on the sorption and desorption behaviors of diuron ; meanwhile same research was conducted for the pesticide pyrimethanil . Sorption and dissipation, environmental fate of insecticide acetamiprid in three typical agricultural soils amended by biochar have been investigated ; and the effect of biochar amendment on the bioavailability of chlorantraniliprole(CAP) in soils and the uptake of CAP by earthworms also have been studied. We investigated the effectiveness of two types of biochars in reducing the bioavailability of pesticides chlorpyrifos and carbofuran to Spring onion (Allium cepa). The results showed that the plant uptake of pesticides decreased markedly with increasing biochar content of the soil . Degradation of pesticides chlorpyrifos and fipronil in rice from farm to fork and risk assessment for human health were studied to reveal the magnitude of risks faced by different populations in china, so that appropriate measures can be taken to control the risks. The results showed that the harvest interval was a critical measure to mitigate risk for all populations for dietary exposure; increasing retreatment intervals and extending interval of harvest will reduce the risk faced by entire populations.
With open mind and interdisciplinary cooperation, we can make good advance in science; you are very welcome to contact us in any co-interested collaboration.
Published paper for your interests：
 LIU Xian-jin，YAN Chun-rong，LIU Yuan，YU Xiang-yang，ZHANG Cun-zheng. Application of Current Hapten in the Production of Broad Specificity Antibodies against Organophosphorus Pesticides. AGRICULTURAL SCIENCES IN CHINA,2008, 7(11):1341-1347.
 ZHANG Cun-Zheng, YANG Chun-Long, LIU Xian-Jin, CHEN Min, YU Jie. An Indirect Competitive Enzyme-Linked Immunosorbent Assay for Determination of New Herbicide H-9201 in Water. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY, 2011, 39(23), 225–230.
 Xiao Zhang，Cunzheng Zhang，Yuan Liu，Xiangyang Yu，Xianjin Liu. Construction of scFv phage display library with hapten-specific repertories and characterization of anti-ivermectin fragment isolated from the library. Eur. Food Res. Technol., 2010, 23:423-430.
 Wen, S., Zhang, X., Liu, Y., Zhang, Q.Q., Liu, X.J., Liang, J.S., 2010. Selection of a single chain variable fragment antibody against ivermectin from a phage displayed library. J. Agric. Food Chem. 58, 5387-5391.
 Zhang, X., Liu, Y., Zhang, C.Z., Wang, Y., Xu, C.X., Liu, X.J., 2012. Rapid isolation of single-chain antibodies from a human synthetic phage display library for detection of Bacillus thuringiensis (Bt) Cry1B toxin. Ecotoxicol. Environ. Safe 81 (1), 84-90.
 Wang, Y., Zhang, X., Zhang, C.Z., Liu, Y., Liu, X.J., 2012. Isolation of single chain variable fragment (scFv) specific for Cry1C toxin from human single fold scFv libraries. Toxicon 60, 1290-1297.
 Zhang, X., ,Xu, C.X., Zhang, C.Z., Liu, Y., Xie, Y.J., Liu, X.J., 2014. Established a new double antibodies sandwich enzyme-linked immunosorbent assay for detecting Bacillus thuringiensis (Bt) Cry1Ab toxin based single-chain variable fragments from a naïve mouse phage displayed library. Toxicon. 81, 13-22.
. He, J., Liang, Y., Fan, M.T., Liu, X.J., 2011. Preparation of anti-idiotype antibodies of O, O-Dimethyl qrganphosphorus pesticides by phage display technology. Chinese Journal of Analytical Chemistry, 2011, 39(2): 178-182.
 Qiang zhang, Xianjin liu, Yuan liu. Aptamers as recognition elements for analysis of small molecules.Asian Journal of Chemistry, 2012, 24(1), 1-6.
 L. Wang, X. Liu, Q. Zhang and C. Zhang. Selection of DNA aptamers that bind to four organophosphorus pesticides. Biotechnol. Lett., 2012,34,(5),869-874;
 He J, Liu Y, Fan M, Liu X. Isolation and identification of the DNA aptamer target to acetamiprid. J Agric Food Chem. 2011,59(5):1582-6
 Cunzheng Zhang, Li Wang, Zhui Tu, Xing Sun, Qinghua He, Zhaojing Lei, Chongxin Xu,Yuan Liu, Xiao Zhang, Jingyi Yang, Xianjin Liu, Yang Xu. Organophosphorus pesticides Detection using Broad specific Single-Stranded DNA based Fluorescence Polarization Aptamer Assay. Biosensors and Bioelectronics, 55(2014), 216–219.
 He Jiang, Shen Yan, Wang donglan, Sun Xing, Fan Mingtao, Liu Xianjin. Dissipation and residues of 2,4-D-dimethylammonium in wheat and soil. Bull. Environ. Contam. Toxicol. (2010) 85:157-159.
 Jiang He, Mingtao Fan, Xianjin Liu. Environmental behavior of profenofos under Paddy field conditions. Bull. Environ. Contam. Toxicol. (2010) 84:771-774.
 Ying Liang, Wen Wang, Yan Shen, Yuan Liu, Xin Jin Liu. Dynamics And Residues Of Chlorpyrifos And Dichlorvos In Cucumber Grown In Greenhouse [J].Food Control. 2012, 26: 231-234.
 Cun-Zheng Zhang, Zhi-Yong Zhang, Xian-Jin Liu，Wayne Jiang, Yi-Dong Wu. Dissipation and environmental fate of herbicide H-9201 in carrot plantings under field conditions, Food Chemistry, 119 (2010): 874-879.
 Xiao Zhang, YanShen, Xiang-yang Yu, Xian-jinLiu. Dissipation of chlorpyrifos and residue analysis in rice, soil and water under paddy field conditions. Ecotoxicology and Environmental Safety 78, (2012),276–280.
 Zhang Zhiyong, Shan Weili, Song Wencheng, Gong Yong, Liu Xianjin. Phytotoxicity and uptake of chlorpyrifos in cabbage. Environ Chem Lett, 2011, 9:547-552.
 Ying Liang, Wen Wang, Yan Shen, Yuan Liu, Xin Jin Liu. Effects of home preparation on organophosphorus pesticide residues in raw cucumber [J]. Food Chemistry. 2012, 133(3）:636-640.
 Haiyan Lu, Yan Shen, Xing Sun, Hong Zhu, Xianjin Liu. Washing effects of limonene on pesticide residues in green peppers. J. Sci. Food Agric. 2013, 93:2917-2921.
 Yu Xiang Yang, Guang-Guo Ying, Rai Kookana. Sorption and desorption behavior of diuron in soil amended with Charcoal. J. Agric. Food Chem. 2006, 54(22): 8545-8550.
 Yu Xiang-Yang, Li-Gang Pan, Guang-Guo Ying, Rai S. Kookana. Enhanced and irreversible sorption of pesticide pyrimethanil by soil amended with biochars [J]. J. of Environ. Sci. 2010, 22(4): 615-620.
 Yu Xiang-Yang, Mu Chang Li, Gu Cheng, Liu Cun, Liu Xian Jin. Impact of woodchip biochar amendment on the sorption and dissipation of pesticide acetamiprid in agricultural soils. Chemosphere, 2011, 85: 1284-1289.
 Ting-Ting Wang, Jie Cheng, Xian-jin Liu, Wayne Jiang, Chao-Lan Zhang, Xiang-Yang Yu. Effect of biochar amendment on the bioavailability of pesticide chlorantraniliprole in soil to earthworm. Ecotoxicology and Environmental Safety 83(2012) 96-101.
 Xiang-Yang Yu, Guang-Guo Ying, Rai S. Kookana. Reduced plant uptake of pesticides with biochar additions to soil. Chemosphere,2009,76(5): 665–671.
 ZHANG Cun-zheng, ZHANG Xin-ming, TIAN Zi-hua, He Dan-jun, LIU Xian-jin. Degradation of Chlorpyrifos and Fipronil in Rice from Farm to Fork and Risk Assessment. Agricultural Sciences in China, 2010, 9(5): 754-763.