A simple enzyme-catalyzed reaction induced "switch" type fluorescence biosensor based on carbon nitride nanosheets for the assay of alkaline phosphatase activity. Issue 19 (17th September 2020)

• Record Type: Journal Article
• Authors: Zhu, Xi; Xu, Huifeng; Zhan, Yan; Li, Wenjing; Dong, Yongqiang; Yu, Lishuang; Chi, Yuwu; Ye, Hongzhi
• Is Part Of: Analyst. Volume 145:Issue 19(2020)
• Page Start: 6277
• Page End: 6282
• Publication Date: 2020-09-17
• Subjects: Chemistry, Analytic -- Periodicals; 543
• DOI: 10.1039/d0an01224f
• Languages: English
• ISSNs: 0003-2654

Abstract

Abstract : An enzyme-catalyzed fluorescence "switch" type sensor was constructed for assay of alkaline phosphatase activity by combining the fluorescence quenching effect of Ag + on ultrathin g-C3 N4 nanosheets with the simple redox reaction of AA and Ag + . Abstract : An enzyme-catalyzed fluorescence "switch" type sensor was constructed for the determination of alkaline phosphatase (ALP) activity by combining the fluorescence quenching effect of Ag + on ultrathin g-C3 N4 nanosheets (CNNSs) with the simple redox reaction of AA and Ag + . Briefly, Ag + exhibits a significant quenching effect on the fluorescence of CNNSs. Thus the fluorescence signal of the CNNS-Ag + system is extremely weak even in the presence of l -ascorbic acid-2-phosphate (AAP) ("off" state). When ALP coexists in the system, the enzyme can specifically catalyze the hydrolysis of AAP to form ascorbic acid (AA), which reduces Ag + to Ag 0 . In this case, the fluorescence signal of the system is recovered ("on" state). Based on this principle, a signal-enhanced CNNS fluorescence sensor was developed to determine the activity of alkaline phosphatase. The experimental results show that the detection range of alkaline phosphatase is 0.5–20 U L −1, and the detection limit is 0.05 U L −1 (S/N = 3). Meanwhile, this method was used to assay ALP in serum samples.