A pH-sensitive fluorescent probe based on hemicyanine dyes for responding microenvironment changes of cardiomyocytes induced by Zn2+

Abstract

The physiological state of myocardium is closely related to human health. Adverse physiological processes will lead to significant fluctuations in cardiomyocytes microenvironment, and even myocardial damage. So, it is particularly necessary to achieve the goal that monitoring cardiomyocytes microenvironment changes. Herein, we developed a new pH-sensitive fluorescent probe (3-ethyl-2-(4-hydroxy-3,5-dimethoxystyryl) benzo[d]thiazol-3-ium hemicyanine, named ETHC). The probe could respond to the pH in solution via both single fluorescence channel and ratio fluorescence as the output signal with great stability and biocompatibility. Then, the effect of Zn2+ on cardiomyocyte microenvironment was successfully monitored by ETHC through the significant changes of red channel fluorescence, which proved that Zn2+, just as resveratrol (Res), had excellent synergistic effect on cardiomyocyte protection. The subsequent carbonyl cyanide 3-chlorophenylhydrazone (CCCP) and ionomycin/Ca2+ treatment confirmed that the decrease of red channel fluorescence was indeed attributed to the acidification of mitochondria in cardiomyocytes. ETHC achieves the monitoring and biological imaging of cardiomyocyte microenvironment changes, which provides a valuable tool for the study of related life event models.