Bifunctional fluorescent probe for the recognition of hydrazine and bisulfite in lipid droplets

Bifunctional fluorescent probes for recognizing different substances have important research significance due to the wide variety of analytes. Here, a triphenylamine structural fluorescent probe (TPA-CHO) for the recognition of hydrazine (N2H4) and bisulfite (HSO3-) in environment and lipid droplets based on aldehyde group sensing site was developed. The probe can detect those analytes with low detection limits and distinguishable color change (0.24 µM, red to green for N2H4; 1.71 µM, red to blue for HSO3-). The reaction mechanism indicates that after reacting with N2H4 and HSO3-, the production of hydrazone or hydroxy methanesulfonate group leads to a different molecular length and intramolecular charge transfer degree and then induces color-differentiated fluorescence emission. This structural design strategy for bifunctional fluorescent probes provides essential ideas for the design of single-molecule dual-analyte target probes.