A Graphene Quantum Dots-Enzyme Hybrid System for the Fluorescence Assay of Alkaline Phosphatase Activity and Inhibitor Screening

Abstract

A graphene quantum dots (GQDs) and horse radish peroxidase (HRP) hybrid system was designed for the sensing of alkaline phosphatase (ALP) activity and inhibitor screening. We found that the photoluminescence (PL) intensity of GQDs could be quenched efficiently in the presence of phenol, H2O2 and HRP. Moreover, ALP could hydrolyze disodium phenyl phosphate (DPP) to produce phenol, and also could result in the photoluminescence quenching of GQDs. The decrease in the PL intensity was linear to the activity of ALP in the concentration range of 0.02 -0.8 U/L, with a detection limit of 0.008 U/L. The proposed GQDs/HRP hybrid system was successfully applied to ALP determination in human serum samples. The inhibition study was further analyzed, and Na3VO4 (as an ALP inhibitor) showed a clear inhibition effect. The results suggest that the GQDs/HRP hybrid system has good potential applications for the assay of ALP activity and inhibitors screening in related biochemical fields.

Gold Nanocluster-catalyzed Luminol Chemiluminescent Sensing Method for Sensitive and Selective Detection of Alkaline Phosphatase

“…7 Therefore, the development of simple and sensitive methods for the detection of ALP activity is of great importance. Over the past few years, a variety of methods including colorimetry, 8,9 fluorescence, [10][11][12] surface-enhanced Raman scattering, 13 electrochemistry, 14,15 photoelectrochemistry, 16 and electrochemiluminescence, 17 have been established for the detection of ALP activity. Although the reported colorimetric methods for ALP detection are simple, the detection sensitivity is poor.…”