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 (HS) 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 HS, 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 HS. 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 for imaging both exogenous and endogenous HS. This work brings new information to the strategy of signal processing by exploiting fluorescent probes.