Study Of The Immunochromatographic Test Strip For Rapid Detection Organophosphorous Pesticides Adducts

In this study,we developed a novel sandwich immunochromatographic test strip(ICTS)which is based on the enzyme inhibition principle.This method enables to simultaneously measure butyrylcholinesterase(BChE)activity and the total amount of BChE(including inhibited and active enzyme)from one post-exposure sample,we can get the amount of inhibited BChE of human by using the total amount of BChE minus active BChE.the BChE monoclonal antibody(MAb)as both capture antibody can recognize OP-BChE and BChE equally.Meanwhile,the Au NPs labeled anti-BChE as detection antibody to detect the total amount of BChE by the color signal of AuNPs.Then,excised the test line from the test-strip for subsequent off-line measurement of BChE activity using the Ellman assay.Therefore,dual biomarkers of BChE activity and phosphorylation(OP-BChE adduct)will be obtained simultaneously.After a series of parameter optimization which including the amount of Au NPs labeled anti-BChE,the working solution and immunoreaction time,we get the excellent linear responses for assaying total amount of BChE and active BChE ranging from 1.0 to 18.75 nM and 1.0 to 37.5 nM,respectively.Both of two signal detection limits are 0.5 nM.Meanwhile,we compared the correlation of ICTS with Ellman assay,the relative deviations are under 10%.We also successfully applied this approach into human blood sample detection,the most of results are consistent with LC-MS,the relative deviations of 70%samples are under 10%.In brief,combining the portability and rapidity of test strip and the compatibility of BChE MAb as both capture antibody and detection antibody,the developed method provides a baseline-free,low-cost and rapid tool for in-field monitoring of OP exposures.