Perovskite Quantum Dots for Fluorescence Turn-Off Detection of the Clodinafop Pesticide in Food Samples via Liquid–Liquid Microextraction
Ghinaiya Nirav Vajubhai, Prabhakar Chetti, Suresh Kumar Kailasa
Abstract
Herein, red fluorescent CsPbI3 perovskite quantum dots (PQDs) are successfully synthesized by a one-step reaction via a microwave irradiation method. The as-fabricated CsPbI3 PQDs displayed a strong emission intensity at 686 nm when applied with a λEx of 350 nm. The as-synthesized CsPbI3 PQDs were dispersed in hexane, and the quantum yield of CsPbI3 PQDs was 27%. The CsPbI3 PQDs were successfully integrated with liquid–liquid microextraction for the analysis of the clodinafop pesticide by fluorescence spectrometry. The emission peak of CsPbI3 PQDs at 686 nm was quenched (∼94%) by the clodinafop pesticide using hexane as a solvent, resulting in a dramatic change in fluorescence from red to nonfluorescence. The sensing mechanism was demonstrated by studying various techniques including fluorescence lifetime, high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, and density functional theory. The developed probe exhibited a good linearity over the concentration of clodinafop in the range of 0.1–5 μM with a limit of detection of 34.70 nM. The CsPbI3 PQDs could be used as a sensor for the quantification of clodinafop in vegetable, fruit, and grain samples. The developed method displayed good recoveries from 97 to 100% with lower relative standard deviations for the analysis of clodinafop in spiked samples, signifying that CsPbI3 PQDs could be used as a promising sensor for the detection of clodinafop in food samples.