Ultra-fast responses NIR fluorescence chemosensor for monitoring HSO3-/SO2 and viscosity as well as its applications in real food samples and living biosystem.

In this work, we presented a NIR fluorescent probe TCB, featuring dual sensing properties for detection of HSO₃-/SO₂ and viscosity. For the first time, the probe exhibits ultra-fast response toward bisulfite (within 10 s). TCB enables efficient and specific sensing of HSO₃-/SO₂ and viscosity at distinct emission wavelengths with the initial emission at 692 nm. The probe exhibits excellent sensing performance toward HSO₃-/SO₂ with a low detection limit of 0.182 μM. Bioimaging experiments confirmed its ability to image both exogenous HSO₃-/SO₂ and viscosity in living cells. Notably, probe TCB facilitated precise imaging of HSO₃-/SO₂ changes in zebrafish and rice roots. Furthermore, the probe was successfully applied to the detection of HSO₃-/SO₂ in food and water samples, achieving satisfactory recovery rates ranging from 91.5 % to 111.5 %, thereby demonstrating its strong compatibility and practical utility in environmental and biological contexts.