Fluorometric determination of ziram using CsPbBr3 quantum dots.

ABSTRACT

A strategy based on CsPbBr3 quantum dots (QDs) is described for the determination of ziram pesticide. A facile and inert gas-free method was used for the synthesis of CsPbBr3 QDs. The obtained CsPbBr3 QDs displayed turn-off fluorescence behavior for ziram. The fluorescence intensity of the CsPbBr3 QDs (Ex/Em = 365/516 nm) was inversely proportional to the concentration of ziram (0.10 to 50.0 ppm) with a detection limit of 0.086 ppm. Notably, satisfactory recoveries (100 ± 0.25 to 107 ± 5.72%) were obtained in spiked fruit samples, which demonstrated that this method is capable of detecting ziram in real samples. In addition, the mechanism for the detection of ziram was investigated in detail. According to the results, this mechanism can be tentatively explained by fluorescence quenching originating from the increased surface defects and the structural changes of the CsPbBr3 QDs. The detection ability of this strategy shows promising applicability in food safety.