An esterase-sensitive AIEgen probe targeting mitochondria and lipid droplets for assessing cell viability

In order to conduct in-depth research on the mechanisms of cancer diagnosis and treatment, it is very important to develop fluorescent probes to study the interactions between different organelles and understand the relationship between various organelles and cell viability. However, the lack of fluorescent probes to visualize two or more targets has resulted in limited studies of intracellular interactions between different organelles. To this end, in this work, we developed a near-infrared (NIR) AIE probe with dual-color emission, NAP-Py-E, for mitochondria and lipid droplets imaging. The probe NAP-Py-E consists of lipophilic fraction, pyridine cation structure and esterase hydrolysis site. Interestingly, NAP-Py-E first targets mitochondria and emits red fluorescence; after partially hydrolyed by esterase in living cells, the hydrolysate NAP-Py accumulates in lipid droplets and emits green fluorescence. The probe has been successfully used to assess cell viability due to its dual-color emission and dual-organelle targeted changes.