title: Organophosphorus pesticides detection using broad-specific single-stranded DNA based fluorescence polarization aptamer assay.
abstract: An approach is developed to detect the organophosphorus pesticides via competitive binding to a recombinant broad-specificity DNA aptamer with a molecular beacon (MB), the binding of the MB to the aptamer results in the activation of a fluorescent signal, which can be measured for pesticide quantification. Aptamers selected via the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) were structurally modified and truncated to narrow down the binding region of the target, which indicated that loops of the aptamer contributed different functions for different chemical recognition. Thereafter, a variant fused by two different minimum functional structures, was clarified with broad specificity and increased affinity. Further molecular docking and molecular dynamics simulations was conducted to understand the molecular interaction between DNA structure and chemicals. 3D modeling revealed a hot spot area formed by 3 binding sites, forces including hydrogen bonds and van der Waals interactions appear to play a significant role in enabling and stabilizing the binding of chemicals. Finally, an engineered aptamer based approach for the detection of organophosphorus pesticides was successfully applied in a test using a real sample, the limit of quantification (LOQ) for phorate, profenofos, isocarbophos, and omethoate reached 19.2, 13.4, 17.2, and 23.4 nM (0.005 mg L(-1)), respectively.
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanjing East Road 235, Nanchang 330047, China; Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety, Jiangsu Academy of Agricultural Sciences, Zhongling Street 50, Nanjing 210014, China.
authors.forename: Cunzheng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety, Jiangsu Academy of Agricultural Sciences, Zhongling Street 50, Nanjing 210014, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanjing East Road 235, Nanchang 330047, China.
authors.forename: Zhui
authors.initials: Z
authors.lastname: Tu
authors.affiliation: Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety, Jiangsu Academy of Agricultural Sciences, Zhongling Street 50, Nanjing 210014, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanjing East Road 235, Nanchang 330047, China.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: He
authors.affiliation: Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety, Jiangsu Academy of Agricultural Sciences, Zhongling Street 50, Nanjing 210014, China.
authors.forename: Zhaojing
authors.initials: Z
authors.lastname: Lei
authors.affiliation: Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety, Jiangsu Academy of Agricultural Sciences, Zhongling Street 50, Nanjing 210014, China.
authors.forename: Chongxin
authors.initials: C
authors.lastname: Xu
authors.affiliation: Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety, Jiangsu Academy of Agricultural Sciences, Zhongling Street 50, Nanjing 210014, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety, Jiangsu Academy of Agricultural Sciences, Zhongling Street 50, Nanjing 210014, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety, Jiangsu Academy of Agricultural Sciences, Zhongling Street 50, Nanjing 210014, China.
authors.forename: Jingyi
authors.initials: J
authors.lastname: Yang
authors.affiliation: Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety, Jiangsu Academy of Agricultural Sciences, Zhongling Street 50, Nanjing 210014, China. Electronic address: jaasliu@gmail.com.
authors.forename: Xianjin
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanjing East Road 235, Nanchang 330047, China. Electronic address: xuyang@ncu.edu.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xu
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000235:genetics; D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D010755:Organophosphates / Q000032:analysis* / Q000737:chemistry; D010575:Pesticides / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*
chemical_list: D052157:Aptamers, Nucleotide; D010755:Organophosphates; D010575:Pesticides
keywords: DNA aptamer; Molecular beacon; Organophosphorus pesticides