Detection of carboxylesterases by an activatable NIR fluorescence probe with high selectivity in living systems

Carboxylesterases (CEs) have attracted increasingly attention in the physiological and pathological processes of many diseases such as diabetes, hepatocellular carcinoma (HCC) and drug metabolism. Selective detection of CEs activity is imperative to evaluate the pathophysiological process of CEs-related disease. Herein, a selective near-infrared (NIR) fluorescent probe (DCM-CE) with high selectivity is reported. DCM-CE was composed of dicyanoisophorone-based fluorophore and carbamate unit which is a highly selective identification group for CEs. DCM-CE exhibited good sensitivity for CEs detection at physiological pH and temperature. Furthermore, DCM-CE featured large Stokes shift (175 nm) and good at tracking the drug-induced trace change of CEs activity in HepG2 cells with little effect on cell viability. Moreover, DCM-CE was applied to monitor the activity of CEs in living mice. Taken all together, DCM-CE had extensive potential application value in detecting CEs for evaluating related diseases.