A novel CdSe/ZnS quantum dots fluorescence assay based on molecularly imprinted sensitive membranes for determination of triazophos residues in cabbage and apple

© 2019 Hong, She, Cao, Wang, He, Zheng, Wang, Abd El-Aty, Hacimüftüoglu, Yan and Wang. In the present study we have developed a direct competitive CdSe/ZnS quantum dot (QD) fluorescence assay based on micro-array-imprinted membranes for the determination of triazophos in cabbage and apple. The imprinted membranes were directly synthesized on the surface of a 96-well plate by thermal polymerization using triadimefon as the dummy template. Under optimal conditions, the assay showed an excellent linear response over the concentration ranges of 0.1-10,000 μg L -1 with a good coefficient of determination (R 2 = 0.982). The sensitivity (IC 50 ) and limit of detection (LOD, expressed as IC 15 ) of the developed assay were 3.63 mg L -1 and 0.31 μg L -1 , respectively. The applicability of the developed approach was tested for detecting triazophos in incurred samples. The method showed excellent recoveries (109.6-118.9%) and relative standard deviations (RSDs) between 9.9 and 19.5%. The obtained results correlated well with those obtained by LC-MS/MS (R 2 = 0.9995). The competitive assay using CdSe/ZnS QDs as fluorescence-labeled probe showed good sensitivity, steady and fast response, and excellent anti-interference ability compared to conventional fluorescence-quenching methods. Finally, the feasibility of the proposed methodology was successfully applied for detection of triazophos in real samples.