Preparation of a Near-Infrared Fluorescent Probe Based on IR-780 for Highly Selective and Sensitive Detection of Bisulfite–Sulfite in Food, Living Cells, and Mice

A near-infrared fluorescent probe was designed and synthesized for the detection of bisulfite–sulfite in food, living HeLa cells, and mice. The probe is a stable hemicyanine skeleton based on IR-780, which produces a distinct color and fluorescence change before and after reaction with bisulfite and shows excellent analytical performance, such as high sensitivity with a detection limit of 0.37 μM and high selectivity toward bisulfite over other substances. More importantly, the probe determined bisulfite in real food samples (crystal sugar and red wine) with superior recoveries (96.7–106.1%) and has been successfully used to monitor bisulfite in living HeLa cells. Notably, the probe was applied to image bisulfite in BALB/c mice in vivo for the first time. Owing to its biocompatibility, this probe provides a desired method to study the metabolism of bisulfite in cells and shows substantial potential usage in other biosystems and in vivo imaging studies.