| Literature DB >> 31776798 |
Xian-En Zhao1, Ya-Nan Zuo1, Xiaoqing Qu1, Jing Sun2, Lingyuan Liu1, Shuyun Zhu3.
Abstract
The authors describe novel colorimetric assays for tyrosinase (TYR) and catalase (CAT) based on the substrate-triggered decomposition of MnO2 nanosheets (NSs). The MnO2 NSs can act as oxidase mimics that catalyze the oxidation of the substrate tetramethylbenzidine (TMB) to form a blue dye with an absorption maximum at 652 nm. The oxidase-mimicking activity of the MnO2 NSs is inhibited by dopamine (DA)/hydrogen peroxide (H2O2) due to their decomposition of the MnO2 NSs. TYR catalyzes the oxidation of DA while CAT can decompose H2O2 into water and oxygen. Therefore, the oxidase-mimicking activity of MnO2 NSs is restored in the presence of both enzymes and their substrates. Based on the competitive consumption of substrates between enzymes and MnO2 NSs, a colorimetric method for determination of enzyme activity and its substrate is developed. The detection limits for TYR and CAT are 6 mU·mL-1 and 33 mU·mL-1, respectively. Graphical abstractA colorimetric method for monitoring enzyme activity and its substrate is described. It is based on the substrate-inhibited oxidase-mimicking activity of MnO2 nanosheets.Entities:
Keywords: 3,3′,5,5’-Tetramethylbenzidine; Catalytic oxidation; Dopamine; Enzyme activities; Human serum analysis; Hydrogen peroxide; Nanozyme; Oxidase mimic; Two-dimensional nanomaterials
Year: 2019 PMID： 31776798 DOI： 10.1007/s00604-019-3995-3
Source DB: PubMed Journal: Mikrochim Acta ISSN： 0026-3672 Impact factor: 5.833