A quinolinium-based fluorescent probe with high quantum yield for bisulfite detection and its applications in food testing, solid-phase immobilization, smartphone-assisted portable detection, and cell imaging.

Abstract

To achieve rapid and accurate detection of bisulfite (HSO3−), we developed two novel fluorescent probes, PTQ and PSQ, featuring large Stokes shifts, a broad detection range, and high fluorescence quantum yields, based on intramolecular charge transfer mechanism. Among them, PTQ exhibits superior selectivity and sensitivity, accompanied by a distinct color change and a strong turn-on fluorescence response upon recognition of HSO3−. Leveraging these properties, PTQ enables the effective detection of HSO3− in food samples. Furthermore, we constructed test strips, agarose gels, and a smartphone-assisted detection platform for the on-site monitoring of SO2 gas and HSO3− in aqueous solutions, and preliminarily explored the potential application of PTQ as an anti-counterfeiting ink. Notably, PTQ also possesses mitochondria-targeting ability, enabling the visualization and imaging of exogenous and endogenous bisulfite in live cells and zebrafish. This work highlights the versatile potential of PTQ in environmental monitoring, food safety inspection, and bioimaging, providing a powerful tool for detecting SO2 derivatives from abiotic samples to living organisms.