Study On The Method And Development Of Test Strips Based On Fluorescence Chromatography For The Detection Of Procymidone In Vegetables

Pesticides are chemical substances used to protect crops from the threat of pests and diseases to promote their healthy growth.They are widely used in agriculture,forestry and other fields.Pesticides are used to increase crop yields to meet the needs of the world’s growing population.In recent years,with the increasing use of procymidone,there are more and more problems,among which the problem of excessive procymidone in vegetables is particularly serious.At present,there are few rapid detection methods for detecting procymidone in vegetables,and the sensitivity and accuracy are low.To address these problems,paper-based sensors for the detection of procymidone in vegetables were designed using time-resolved fluorescent microspheres as the material.The main research contents and results are as follows:(1)In this paper,time-resolved fluorescent immunochromatography strips(TRFICS)based on the principle of antigen-antibody immunocompetition were developed for the detection of procymidone in vegetables.Sample were added dropfully to TRFICS and TRFICS were incubated at 37°C for 10 min.The results were observed under a UV lamp of 365 nm and images were processed by Image J software to complete qualitative and quantitative analyses.Under the optimal working conditions,the linear range of TRFICS was 5 ng/m L～250 ng/m L,the limit of detection(LOD)was 0.33 ng/m L,and the visual detection limit(VDL)was 50 ng/m L.When the results of TRFICS were compared with those of ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS),they were in good agreement between the two assays,indicating that the method of TRFICS was feasible.(2)In order to further improve the sensitive of the detection of procymidone in vegetables,three kinds of europium oxide time-resolved fluorescent immunochromatographic strips(EuTRFICS)based on core biological immune scaffolds were developed.The time-resolved fluorescent microspheres and the goat anti-mouse antibody formed secondary probes,and the procymidone monoclonal antibody and the secondary probes together formed the core biological immune scaffolds.The first europium oxide time-resolved fluorescent immunochromatographic strip(Eu-TRFICS-(1))immobilized the secondary probes on the conjugate pad,and the procymidone monoclonal antibodies were mixed with the sample solution.The second europium oxide time-resolved fluorescent immunochromatographic strip(Eu-TRFICS-(2))immobilized core biological immune scaffolds on a conjugate pad.The third europium oxide time-resolved fluorescent immunochromatographic strip(Eu-TRFICS-(3))was that core biological immune scaffolds mixed with the sample solution directly on the sample pad in a drop.The Eu-TRFICS showed stronger detection signals while achieving qualitative and quantitative detection.Core biological immune scaffolds were targeted to immobilize procymidone monoclonal antibodies,which perfectly exposed the antigen binding site,reduced the amount of antibody used and increased the utilization of the antibody.Therefore,Eu-TRFICS have the advantages of lower price,higher sensitivity,broader detection range,high specificity and simple operation,which provide a reference value for the establishment of other TRFICS.