BSA-Stabilized Silver Nanoclusters Enhanced Fluorescence of a Dicyanoisophorone Derivative With o-Vanillin for Sensitive Detection of Hydrogen Sulfide (H2S).

The endogenous hydrogen sulfide (H2S) is a vital signaling molecule and plays an important role in the physiological processes. Its abnormal level can cause various detrimental effects. Thus, there is a bourgeoning need to develop facile and sensitive methods for detecting H2S in various biological samples. Herein, a fluorescence-based sensing platform has been developed for the ultrasensitive detection of H2S using an aggregation-induced emission (AIE) active dicyanoisophorone derivative with o-vanillin (DSVL). AIE luminogen (AIEgen) fluorescence emission at 530 nm was quenched selectively by H2S, which enables its detection with a detection limit of 3.88 µM. Interestingly, when the probe DSVL was interacted with bovine serum albumin-stabilized silver nanoclusters (BSA-AgNCs), the formation of nanocomposite BSA-AgNCs_DSVL resulted a significant enhancement in the relative quantum yield of DSVL from 31.88% to 83.84%. The highly fluorescent nanocomposite BSA-AgNCs_DSVL showed an improved sensitivity with the detection limit down to 0.86 nM. Finally, the analytical utility was examined by detecting H2S in real samples, such as blood serum and vegetable extracts.