Abstract

Rice-shaped protein–copper oxide hybrid (RSPCO) was prepared by one-pot method in the presence of amphiphilic proteins. The enzyme-mimicking activity of RSPCO depends much on the substrate structure. RSPCO shows superior peroxidase-like activity with 3,3′,5,5′-tetramethylbenzidine (TMB) as a substrate. RSPCO exhibits both peroxidase- and oxidase-like activities with 1,2-diaminobenzene (OPD) as the substrate. RSPCO does not exhibit peroxidase-/oxidase-like activity when using 2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonic acid)diammonium salt (ABTS) as the substrate. Furthermore, pyrogallol (PA)-induced activity switching effect is dependent on the type of enzyme-like activity of nanozyme and the substrate structure. The different effect of PA on the enzyme-like activity of RSPCO attributes mainly to the different affinity of substrates toward RSPCO. PA can significantly inhibit the peroxidase-like activity of RSPCO with TMB used as the substrate. Due to the efficient inhibiting effect, an excellent PA colorimetric sensor with low limit of detection being 15 nM (signal-to-noise ratio of 3) was developed based on RSPCO. With the features of simplification and low cost, protein–copper oxide hybrid nanozymes has the potential application in medial, environmental, and food areas. The present work provides new information about activity–structure relationship of copper oxide nanozyme, which is important for the applications of nanozymes in practice.

摘要

在两亲蛋白存在的情况下，通过一锅法制备稻形蛋白-氧化铜杂化物（RSPCO）。RSPCO 的酶模拟活性很大程度上取决于底物结构。以 3,3',5,5'-四甲基联苯胺 (TMB) 作为底物，RSPCO 显示出优异的过氧化物酶样活性。RSPCO 表现出以 1,2-二氨基苯 (OPD) 作为底物的过氧化物酶和氧化酶样活性。当使用 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) 二铵盐 (ABTS) 作为底物时，RSPCO 不表现出过氧化物酶/氧化酶样活性。此外，邻苯三酚（PA）诱导的活性转换效应取决于纳米酶的酶样活性类型和底物结构。PA对RSPCO酶样活性的不同影响主要归因于底物对RSPCO的不同亲和力。PA可以显着抑制以TMB为底物的RSPCO的过氧化物酶样活性。由于有效的抑制效果，基于RSPCO开发了一种检测下限为15 nM（信噪比为3）的优秀PA比色传感器。蛋白质-氧化铜杂化纳米酶具有结构简单、成本低廉等特点，在医药、环境和食品等领域具有潜在的应用前景。目前的工作为氧化铜纳米酶的活性-结构关系提供了新的信息，这对纳米酶在实践中的应用具有重要意义。由于有效的抑制效果，基于RSPCO开发了一种检测下限为15 nM（信噪比为3）的优秀PA比色传感器。蛋白质-氧化铜杂化纳米酶具有结构简单、成本低廉等特点，在医药、环境和食品等领域具有潜在的应用前景。目前的工作为氧化铜纳米酶的活性-结构关系提供了新的信息，这对纳米酶在实践中的应用具有重要意义。由于有效的抑制效果，基于RSPCO开发了一种检测下限为15 nM（信噪比为3）的优秀PA比色传感器。蛋白质-氧化铜杂化纳米酶具有结构简单、成本低廉等特点，在医药、环境和食品等领域具有潜在的应用前景。目前的工作为氧化铜纳米酶的活性-结构关系提供了新的信息，这对纳米酶在实践中的应用具有重要意义。