A high-performance dual-modal probe boosted by pKa manipulation for colorimetric and fluorescent detection of hydrogen sulfide in living cells and food spoilage

Since hydrogen sulfide (H2S) plays a vital role in physiological functions, it is significant to assess the dynamic levels of H2S in cellular levels and real samples. Nonetheless, a noteworthy challenge lies in the fluorescence fluctuations of probes partly attributed to the comparatively elevated pKa values, thereby complicating the achievement of consistent and stable responses. Herein, a strategy of pKa manipulation was proposed to address the dilemma, and a high-performance colorimetric and fluorescent probe CFB-H2S was rationally developed with a wide pH adaption range of 6.0-10.0. Significantly, the probe exhibits high sensitivity with superior signal-tonoise to 81-fold, rendering more benefits for application of H2S detection. Meanwhile, CFB-H2S can monitor Cysinduced H2S generation in living cells with excellent biocompatibility and low cytotoxicity. Importantly, CFBH2S-based portable test strips were well prepared and its practical applicability was successfully verified in real food spoilage cases.