Construction of a novel fluorescent probe based on a carbazole platform for the rapid and specific detection of H2S and its application in bioimaging and food detection

Abstract

Hydrogen sulfide (H₂S) is an important gaseous signaling molecule that plays an indispensable role in various physiological processes within the human body. To gain a deeper understanding of the role of H₂S in these processes, it is essential to track specific changes in H₂S levels within complex environments and physiological conditions. In this study, we report a novel compound, 9-(4-(2,4-dinitrophenoxy)phenyl)-9H-carbazole, a fluorescent probe (CZ-CDNB) based on the carbazole structure. The probe releases a hydroxyl group (CZ-OH) through the sulfurization reaction, which halts electron transfer in the carbazole, resulting in enhanced fluorescence. CZ-CDNB exhibits high selectivity for H₂S, excellent anti-interference performance, and a broad pH tolerance range (2.0–9.0). It demonstrates a maximum fluorescence enhancement of 108 fold and a low detection limit (LOD = 27 nM). Furthermore, this probe is suitable for monitoring food quality and boasts low toxicity and excellent cell imaging capabilities.