Novel Electrochemical Immunosensor Based on an Abs-AuNPs@ZIF-67 Probe for the Simultaneous Detection of Fenpropathrin and Deltamethrin in Vegetables
Yaodong Xiang, Haowei Dong, Rui Xu, Jingcheng Huang, Guangxian Wang, Fukai Guan, Honggang Fang, Yemin Guo, Mohamed Ahmed
Abstract
To solve the problem of uniform immobilization of gold-labelled antibodies on an electrode surface, an antibody-labelled Abs-AuNPs@ZIF-67 probe was synthesized by a one-step wet chemical method, and an electrochemical immunosensor based on gold-labelled antibody probes for the detection of pyrethroid (PYR) pesticides was constructed. This method enhanced the uniform dispersion effect of gold-labelled antibodies on the electrode surface and improved the immobilization level of broad-spectrum antibody. The detection ranges for fenpropathrin and deltamethrin were determined to be 0.286-2.864 × 10 5 nM and 1.979-1.979 × 10 5 nM, with linear correlation coefficients of 0.9941 and 0.9874, respectively. The limits of detection for fenpropathrin and deltamethrin were determined to be 0.0258 nM and 1.712 nM, respectively. This detection method was compared with the standard GC-MS method for the determination of PYRs in vegetable samples. The electrochemical immunosensor showed a high recovery rate (93.69%-102.11%) in a spiked sample recovery experiment. The constructed electrochemical immunosensor shows high sensitivity, selectivity and stability. This study not only provided a new gold-labelled antibody probe for the rapid detection of fenpropathrin and deltamethrin but also provided a new pathway for the construction of electrochemical immunosensors for the detection of other pesticides and small molecule targets.