A rapid and sensitive fluoroimmunoassay based on quantum dot for the detection of chlorpyrifos residue in drinking water

摘要

A rapid and sensitive indirect competitive fluorescence-linked immunosorbent assay (cFLISA) method based on quantum dots as the fluorescence label coupled with secondary antibody (Ab₂) for the detection of chlorpyrifos in drinking water has been developed. The cFLISA method allowed for chlorpyrifos determination in a liner working range of 15.2-205.5 ng mL−1. The 50 % inhibition value (IC₅₀) and the limit of detection (LOD) of the cFLISA were 50.2 ng mL−1 and 8.4 ng mL−1, while the IC₅₀ and the LOD of the conventhional enzyme linked immunosorbent assay (ELISA) were 95.3 ng- mL−1 and 16.2 ng mL−1, respectively. When the concentrations of chlorpyrifos were 200, 100 and 50 ng mL−1, the recoveries ranged from 90.8 % to 108.2 % with a coefficient of variation (CV) of 7.5 %-15.2 %. In water sample analysis, the results of cFLISA were similar to those obtained from a cELISA and a high performance liquid chromatography (HPLC) method, while the detection time by cFLISA was reduced 0.5 h compared with ELISA. It showed that cFLISA could be used as a new screening method for the detection of pesticide residue.