Standardized assays for determining the catalytic activity and kinetics of peroxidase-like nanozymes

• Published in: Nature protocols Vol. 13; no. 7; pp. 1506 - 1520
• Main Authors: Jiang, Bing, Duan, Demin, Gao, Lizeng, Zhou, Mengjie, Fan, Kelong, Tang, Yan, Xi, Juqun, Bi, Yuhai, Tong, Zhou, Gao, George Fu, Xie, Ni, Tang, Aifa, Nie, Guohui, Liang, Minmin, Yan, Xiyun
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.07.2018
• Subjects: Assaying; Biological activity; Biological properties; Catalysis; Catalytic activity; Diagnostic systems; Enzymes; Haloperoxidase; Iron oxides; Kinetics; Nanomaterials; Nanoparticles; Nanotechnology; Peroxidase; Physicochemical properties; Reaction kinetics; Superoxide dismutase
• ISSN: 1754-2189; 1750-2799
• DOI: 10.1038/s41596-018-0001-1

Nanozymes are nanomaterials exhibiting intrinsic enzyme-like characteristics that have increasingly attracted attention, owing to their high catalytic activity, low cost and high stability. This combination of properties has enabled a broad spectrum of applications, ranging from biological detection assays to disease diagnosis and biomedicine development. Since the intrinsic peroxidase activity of Fe O nanoparticles (NPs) was first reported in 2007, >40 types of nanozymes have been reported that possess peroxidase-, oxidase-, haloperoxidase- or superoxide dismutase-like catalytic activities. Given the complex interdependence of the physicochemical properties and catalytic characteristics of nanozymes, it is important to establish a standard by which the catalytic activities and kinetics of various nanozymes can be quantitatively compared and that will benefit the development of nanozyme-based detection and diagnostic technologies. Here, we first present a protocol for measuring and defining the catalytic activity units and kinetics for peroxidase nanozymes, the most widely used type of nanozyme. In addition, we describe the detailed experimental procedures for a typical nanozyme strip-based biological detection test and demonstrate that nanozyme-based detection is repeatable and reliable when guided by the presented nanozyme catalytic standard. The catalytic activity and kinetics assays for a nanozyme can be performed within 4 h.