Lysosome targeting metal-organic framework probe LysFP@ZIF-8 for highly sensitive quantification of carboxylesterase 1 and organophosphates in living cells

Highlights: • A LysFP@ZIF-8 metal-organic framework (MOF) was fabricated for selectively detection of carboxylesterase 1 (CES1). • LysFP@ZIF-8 with lysosome labeling ability and can be used for monitoring CES1 activities in living cells. • LysFP@ZIF-8 was successfully applied to the quantitative detection of endogenous and exogenous carboxylesterase 1. • LysFP@ZIF-8 has been successfully used as an effective tool in pesticide residue detection. Herein, a lysosomal targeting LysFP@ZIF-8 metal-organic framework (MOF) was fabricated using fluorescent protein chromophore-based probe (LysFP) for selectively detection of carboxylesterase 1 (CES1) in living cells. Unlike the regular small molecule fluorescent probes, LysFP@ZIF-8 showed wide range pH tolerabiligy, high selectivity and sensitivity to CES1 in bio-samples, and was successfully applied to achieve the visual monitoring of CES1 activity in living cells. Low detection limit and high fluorescence quantum yield was calculated as 79 ng/mL and 0.76 for LysFP@ZIF-8, respectively. Furthermore, LysFP@ZIF-8 can also serve as a fluorescence indicator of organophosphates pesticide exposure in the way of hydrolyzing the carboxylic acid ester group in LysFP. This type of probe can inspire the development of fluorescent tools for further explore many pathological processes.