A highly selective and sensitive fluorescence probe based on BODIPY-cyclen for hydrogen sulfide detection in living...

Hydrogen sulfide (H₂S) is a multifunctional gaseous signaling molecule that plays a vital role in several biological processes. In the present study, a BODIPY-based fluorescent probe called 8-[4-((1,4,7,10-tetraazacyclododecane)methyl)phenyl]-4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a, 4a-diaza-s-indacene (BA-Cyclen)-Cu was designed and synthesized; this probe is a Cu(Ⅱ) complex that uses Cu(Ⅱ) decomplexation to achieve the sensitive and rapid detection of aqueous H₂S via the "turn-on" mode. We observed that BA-Cyclen-Cu exhibited good membrane permeability, low toxicity, and lysosome-targeting ability, facilitating H₂S detection in living cells. Furthermore, we demonstrated the potential biological applications of the probe by measuring exogenous H₂S originating from Na₂S and GYY4137, a slow-release donor, and endogenous H₂S generated via the catalysis of cystathionine-β-synthase in both normal (H9c2) and cancerous (U87) cells. Moreover, BA-Cyclen-Cu was successfully used to detect exogenous H₂S by the external standard method in fetal bovine serum, the serum of a healthy person, and the serum of a patient with liver cancer.