氮掺杂中空碳球氧化物模拟酶性能研究

Performance of Nitrogen-doped Hollow Carbon Spheres as Oxidase Mimic

纳米酶由于其独特、高效、稳定的催化性质而在生化反应中备受关注。本研究以碳酸钙微球为绿色模板剂,多巴胺为氮源与碳源,合成了氮掺杂中空碳球(N-HCSs)。以3,3',5,5'-四甲基联苯胺(TMB)为底物,采用紫外分光光度法探究了N-HCSs的类氧化物酶的催化活性,并研究其催化机理。结果表明,N-HCSs具有氧化物模拟酶催化活性,KOH活化后氮掺杂中空碳球的催化活性提高了3倍;N-HCSs氧化物模拟酶催化反应符合Michaelis-Menten方程,活化前后的米氏常数K_(m)分别为0.105和0.083,对底物具有良好的亲和能力;N-HCSs氧化物模拟酶催化反应中起主要作用的活性氧基团是超氧阴离子(O2^(·–))。本研究为高活性无机非金属类氧化物模拟酶的设计和制备提供了理论依据。

Due to efficient performance and stability,nanozymes have recently attracted much attention in bioreaction.In this work,a facile approach for preparing N-doped hollow carbon sheres(N-HCSs)by using CaCO3 spheres as green template and polydoamine as nitrogen and carbon sources was reported.Morphologies and structures of the samples were characterized.Using TMB(3,3,5,5' tetramethylbenzidine)as a substrate,UV spectra photometry was used to investigate its oxidase-like activity and catalytic mechanism.The results showed that N-HCSs displayed oxidase-like activity.The oxidase-like activity of N-HCSs increased by three times after activation by KOH.These enzymes conform to the Michaelis-Menten kinetic equation,and the K_(m)constant before and after activation were 0.105 and 0.083,respectively,indicating good affinity for substrates.The data demonstrate that it is superoxide anion(O2^(·–))that plays a major role in catalytic reaction.This work data provides a theoretical basis for the design and preparation of high activity oxidase-mimicking enzymes.