Detection of lipase activity in human serum based on a ratiometric fluorescent probe

Acute pancreatitis results in major mortality and morbidity. Lipase is a vital biomarker of acute pancreatitis in the early stage. Developing a simple and convenient methodology for monitoring the lipase activity is of significance to the early diagnosis of acute pancreatitis. In this work, we designed a novel ratiometric fluorescent probe (CARA) based on FRET for detecting lipase activity in human serum. The energy donor group coumarin derivative (CA) and the energy acceptor group rhodamine derivative (RA) were linked for the construction of a coumarin-rhodamine platform through an ester bond that is easily cleaved by lipase, breaking the FRET process between CA and RA. CARA shows a high selectivity to lipase over other biological substances and a good linearity between the fluorescence ratio and lipase activity in serum samples. CARA has the potential to be applied in the clinical diagnosis of acute pancreatitis. CARA can monitor lipase activity through hydrolyzing the ester bond to interrupt the FRET process.