Study On The Determination Of Nereistoxin-related Pesticides Based On Optical Sensing System

In recent years,food safety issues caused by pesticide residues have attracted more and more attention.The nereistoxin-related pesticides are widely used in pest control on crops by targeting the acetylcholine receptors(ACh Rs)of pest.However,the excessive use,misuse,or low utilization could cause food contamination and threaten human health and life safety.Therefore,it is of great significance to establish a convenient,fast,and sensitive analysis method of pesticide residues.Herein,we combined the fluorescence analysis and chemical sensing materials to prepare molecularly imprinted fluorescence sensing materials and multi-dimensional optical response sensing materials,with the advantages of easy operation,high sensitivity,low detection limit,high selectivity,and strong specificity.The optical sensing materials analysis towards nereistoxin-related pesticides from one-dimension to multi-dimension was achieved.The details and results are summarized as follows:(1)A molecularly imprinted photoluminescence sensing materials based on functionalized room temperature ionic liquid-strengthened sulfur-doped carbon nanodots(IL-strengthened S-Cdots)was developed by a one-pot strategy.The morphology and structure of sensing materials was characterized by SEM,TEM and other tests.The fluorescence response for cartap detection had a linear range in 1-100?g L^-1,and the linear equation is F₀/F=0.9119+0.0146[C](R²=0.9960)with the detection limit of 0.86?g L^-1.The results of recoveries and optosensing of cartap in food matrices indicated the excellent ability of the prepared IL-strengthened S-Cdots to recognize cartap in complex food matrices and the potential of this method for application in cartap detection.(2)A quantum dot-doped covalent organic framework in a molecularly imprinted network(QDs-doped COFs@MIP)was developed for detection of residual thiosultap in tap water.The morphology and structure of optical sensing materials was characterized by SEM,FT-IR and other tests.Simultaneous detection was established in the ranges 0-0.1?g g^-1(R²=0.9699)and 0.2-2.5mg g^-1(R²=0.9962)by direct sediment fluorescence detection and indirect supernatant ultraviolet detection,respectively,with a low detection limit of 1.8?g kg^-1.Recoveries of spiked water samples indicated the detection system was feasible for tracing thiosultap with high accuracy,and could be applied to other food matrices.(3)A multi-dimensional optical sensing materials based on VBim BF₄B/MAA-sensitized Mn-Zn S quantum dot grafting covalent organic framework[(V-M)/QD-grafted COFs)]was established by a one-pot strategy.The morphology and structure of multi-dimensional sensing materials was characterized by TEM,TGA and other tests.The response(FL,Ph,LS)of multi-dimensional optical sensors to analtye were mersured by spectral titration,and fingerprints for the multiple pesticides were gernerated.By principal component analysis and clustered heatmap analysis,it was found that the multi-dimensional optical sensor array can distinguish the seven pesticides at the level of 200?g L^-1,and further realized the discrimination of these pesticides in the complex food matrix,which verfied the application of multi-dimensional optical sensor array in practice.