Development of phage immuno-loop-mediated isothermal amplification assays for organophosphorus pesticides in agro-products.

Xiude Hua, Wei Yin, Haiyan Shi, Ming Li, Yanru Wang, Hong Wang, Yonghao Ye, Hee Joo Kim, Shirley J Gee, Minghua Wang, Fengquan Liu, Bruce D Hammock

Index: Anal. Chem. 86(16) , 8441-7, (2014)

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Abstract

Two immuno-loop-mediated isothermal amplification assays (iLAMP) were developed by using a phage-borne peptide that was isolated from a cyclic eight-peptide phage library. One assay was used to screen eight organophosphorus (OP) pesticides with limits of detection (LOD) between 2 and 128 ng mL(-1). The iLAMP consisted of the competitive immuno-reaction coupled to the LAMP reaction for detection. This method provides positive results in the visual color of violet, while a negative response results in a sky blue color; therefore, the iLAMP allows one to rapidly detect analytes in yes or no fashion. We validated the iLAMP by detecting parathion-methyl, parathion, and fenitrothion in Chinese cabbage, apple, and greengrocery, and the detection results were consistent with the enzyme-linked immunosorbent assay (ELISA). In conclusion, the iLAMP is a simple, rapid, sensitive, and economical method for detecting OP pesticide residues in agro-products with no instrumental requirement.