A human serum albumin-binding-based fluorescent probe for monitoring hydrogen sulfide and bioimaging

In this work, a fluorescent probe, TPABF-HS, was developed for detecting hydrogen sulfide (H₂S) using a human serum albumin (HSA)-binding-based approach for amplifying the fluorescence signal and extending the linear correlation range. Compared to the most recent probes for H₂S, the most interesting feature of the detection system developed herein was the especially wide linear range (0-1000 μM (0-100 eq.)), which covered the physiological and pathological levels of H₂S. TPABF-HS could be used in applications high sensitivity and selectivity with an LOD value of 0.42 μM. Further, site-competition experiments and molecular docking simulation experiments indicated that signal amplification was realized by the binding of the TPABF fluorophore to the naproxen-binding site of HSA. Moreover, the extension of the measurement span could allow for applications in living cells and Caenorhabditis elegans for imaging both exogenous and endogenous H₂S. This work brings new information to the strategy of signal processing by exploiting fluorescent probes.