Determination of alkaline phosphatase activity based on enzyme-triggered generation of a thiol and the fluorescence quenching of silver nanoclusters
Minchuan Luo1 , Zhu Su1 ,Xinyi Wang1 , Liang Li2 , Yifeng Tu1, Jilin Yan1, *（严吉林）
1 The Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren’ai Road, Industrial Park, Suzhou 215123, China
2 School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430205, China
Microchimica Acta，2019, 186（3）:180
A fluorimetric method is described for the determination of alkaline phosphatase (ALP) activity. It is based on the use of polyethyleneimine-coated silver nanoclusters (AgNCs), which display an intense blue fluorescence peaking at 450 nm (under 375 nm excitation). ALP catalyzes the dephosphorylation of the thiophosphate amifostine to generate a thiol that binds to the AgNCs and causes its fluorescence to be quenched. Under the optimal experimental conditions, fluorescence linearly drops in the 0.08–2.0 U L−1 ALP activity range, and the limit of detection is 0.02 U L−1. The method was successfully applied to the determination of ALP activity in spiked human serum samples.