High-fidelity spatio-temporal recognition of mitochondrial esterase with an on-demand photoactivation strategy

Multiple signaling molecules work together in mitochondria to mediate complex physiological processes. However, most current fluorescent probes lack of ability to clarify the function of these actives in mitochondria due to their non-specific binding with analytes outside mitochondria. In this study, we designed an on-demand light-activated mitochondria-targeted fluorescent probe to observe in situ fluctuations in mitochondrial esterase. The designed probe has a natural yellow fluorescence that monitors entry into the mitochondria and maintains nonfluorescent responsiveness to esterase during cellular delivery. Following the enrichment of the probe in mitochondria, on-demand photoactivation only at the required mitochondrial location resulted in a remarkable emission response to the esterase with red fluorescence at 700 nm. Precise spatiotemporal recognition of esterase in mitochondria is successfully achieved by activating the in situ fluorescence response of esterase by light irradiation. This work provides a new strategy for the study of esterase-related diseases.