N-Positive ion activated rapid addition and mitochondrial targeting ratiometric fluorescent probes for in vivo cell H2S imaging

Heterocyclic compound quinoline and its derivatives exist in natural compounds and have a broad spectrum of biological activity. They play an important role in the design of new structural entities for medical applications. Similarly, indoles and their derivatives are found widely in nature. Amino acids, alkaloids and auxin are all derivatives of indoles, as are dyes, and their condensation with aldehydes makes it easy to construct reaction sites for nucleophilic addition agents. In this work, we combine these two groups organically to construct a rapid response site (within 30 s) for H2S, and at the same time, a ratiometric fluorescence response is presented throughout the process of H2S detection. As such, the lower detection limit can reach 55.7 nmol/L for H2S. In addition, cell imaging shows that this probe can be used for the mitochondrial targeted detection of endogenous and exogenous H2S. Finally, this probe application was verified by imaging H2S in nude mice.