A Smart Tp-Fret-Based Ratiometric Fluorescent Sensor For Bisulfite/Formaldehyde Detection And Its Imaging Application

Bisulfite (HSO3-) and formaldehyde (FA) are hazardous environmental pollutants that pose serious risks to human health. Herein, we report for the first time a novel TP-FRET-based TP-ratiometric reversible fluorescence sensor NPXH, which is based on combining TP naphthalimide fluorophore with a deep red-emitting xanthene fluorophore via a nonconjugated linker, for reversible detection of bisulfite/formaldehyde. In presence of HSO3-, NPXH shows a significant ratio enhancement (similar to 6-fold) in I-535/I-630, ultra-fast response (less than 8 s) and super low detection limit (7.48 nM). In addition, the fluorescence signal of NPXH is easily and rapidly recovered by FA within 1 min. More impressively, NPXH has shown excellent detection capability in food and water samples and has been successfully applied to HSO3-/FA detection in liver tissue, zebrafish and mice.