BODIPY-based selenides as fluorescent probes for rapid, sensitive and mitochondria-specific detection of hypochlorous acid
Hypochlorous acid (HClO) is a powerful microbicidal agent in the innate immue system, however, abnormal HClO level can lead tissue damage and many diseases. Thus, it is vital important to develop facile, rapid and accurate analytical methods for the detection of HClO/ClO- in vitro and in vivo. In this work, we have constructed three 8-subsituted BODIPY selenides with different hydrocarbyl groups (ethyl for BSe-Et, benzyl for BSe-Bz and phenyl for BSe-Ph) as fluorescent probes for the detection of HClO/ClO-. All three non-fluorescent probes can sense HClO/ClO- to form fluorescent selenoxides due to blocking the photo-induced electron transfer process. The sensing property displays a clear relationship with the structures of hydrocarbyls of three probes. The sensing reactivity is heavily dependent on the electron-donating ability of hydrocarbyls, the order of the response time, BSe-Et (2 s) < BSe-Bz (5 s) << BSe-Ph (>100 s). Both BSe-Et and BSe-Bz afford a large fluorescence response and very low detection limits (0.3 nM and 0.8 nM), and BSe-Bz displays more highly selectivity over BSe-Et. Finally, as a representative, BSe-Bz was successfully applied to the detection of exo- and endogenous HClO in living cells, and demonstrated to be a mitochondria-localized fluorescent probe.