化学发光法快速筛选纳米微粒模拟酶

Fast screening of the nanoparticles-based enzyme mimetics by a chemiluminescence method

本文提出了一种基于化学发光法快速筛选纳米微粒模拟酶的新方法,以H2O2-鲁米诺化学发光反应为模型体系,对CoFe2O4、CuFe2O4、-Fe2O3、MnFe2O4、NiFe2O4前驱体和MgFe2O4前驱体等6种铁氧体纳米微粒的过氧化物模拟酶活性进行快速筛选,并与辣根过氧化物酶(HRP)进行比较.结果表明:(1)与HRP类似,6种铁氧体纳米微粒均能够催化H2O2氧化鲁米诺产生增强化学发光,其催化活性依赖于pH、温度以及底物(H2O2)浓度;6种铁氧体纳米微粒均能够催化H2O2氧化TMB的显色反应,表明其具有过氧化物模拟酶特性;(2)以H2O2为底物的表观米氏常数(Km)从小到大依次为CoFe2O4-Fe2O3NiFe2O4前驱体CuFe2O4MnFe2O4MgFe2O4前驱体;(3)铁氧体纳米微粒模拟酶比HRP具有更佳的pH及温度耐受能力.本法简单、快速,可用于大规模纳米微粒模拟酶的快速筛选.

This work put forward a chemiluminescence method for rapid screening of nanoparticles-based mimetic enzymes, which is based on H202-1uminol chemiluminesent reaction as a model system and six ferrite nanoparticles, namely, CoFe204, CuFe204, 7-Fe203, MnFe204, precursor of NiFe204 and precursor of magnesium ferrite as mimetic enzymes, and the results were compared with that of horseradish peroxidase （HRP）. The results indicate： （1） Like HPR, the six ferrite magnetic nanoparticles are able to catalyze the oxidation of luminol by H202 to produce enhanced chemiluminescence, and the catalytic activity of the studied six ferrite magnetic nanoparticles depends on the pH, temperature and substrate （H202） concentration. Also, they could catalytically oxidize 3,3＇,5,5＇-tetramethyl benzidine （TMB） by H202 to produce a typical colour reaction. These results show that the ferrite magnetic nanoparticles possess intrinsic peroxidase properties. （2） The apparent Michaelis constants （Kin） using H202 as substrates were higher than that of HRP, in the order of CoFe204 〈 7-Fe203 〈 precursor of NiFe204 〈 CuFe204 〈 MnFe204 〈 precursor of magnesium ferrite. （3） The ferrite magnetic nanoparticles show better pH and temperature tolerance than HRP. The proposed method promises the advantages of simplicity and rapidity, thus can be used for screening of the nanoparticles-based mimetic enzymes in large scale.