Rapid sulfite screening using nitrobenzofurazan anchored asymmetric naphthorhodamine via electrostatic attraction mediated reaction kinetics

Abstract The performance adjustment of known response motifs is important to further expand their practical applications. In this study, a fluorescent probe based on nitrobenzofurazan response motif anchored structurally asymmetric naphthorhodamine, named NRH-NBD, has been reported for the rapid and selective sulfite screening via a fluorescence turn-on strategy. The fluorescence sensing mechanism utilizes the nucleophilicity of sulfite and the electrostatic attraction mediated reaction kinetics. This interesting integration makes this sensing platform capable to distinguish sulfite from sulfide, metal ions, anions and even thiolates. Using NRH-NBD as the sensing probe, the detection limit toward sulfite is 70 nM with a fluorescence spectrophotometer. In addition, the practicability of this proposed sensing platform is validated by intracellular and endogenous sulfite imaging. Furthermore, the proposed NRH-NBD probe could be applied for sulfite examination in Chinese white wine samples with high accuracy and small relative standard deviation values.