title: Peroxidase-like activity of the Co3O4 nanoparticles used for biodetection and evaluation of antioxidant behavior.
abstract: Nanostructured enzyme mimics are of great interest as promising alternatives to artificial enzymes for biomedical and catalytic applications. Studying the chemical interactions between antioxidants and nano-enzymes may result in a better understanding of the antioxidant capability of antioxidants and may help improve the function of artificial enzymes to better mimic natural enzymes. In this study, using Co3O4 nanoparticles (NPs) as peroxidase mimics to catalyze the oxidation of chromophoric substrates by H2O2, we developed a platform that acts as a biosensor for hydrogen peroxide and glucose and that can study the inhibitory effects of natural antioxidants on peroxidase mimics. This method can be applied specifically to glucose detection in real samples. Three natural antioxidants, gallic acid (GA), tannic acid (TA), and ascorbic acid (AA), were compared for their antioxidant capabilities. We found that these three antioxidants efficiently inhibit peroxidase-like activity with concentration dependence. The antioxidants showed different efficiencies, in the following order: tannic acid > gallic acid > ascorbic acid. They also showed distinct modes of inhibition based on different interaction mechanisms. This study serves as a proof-of-concept that nano-enzyme mimics can be used to evaluate antioxidant capabilities and to screen enzyme inhibitors.
authors.affiliation: Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, Xuchang University, Xuchang, Henan 461000, P. R. China. heweiweixcu@gmail.com.
authors.forename: Huimin
authors.initials: H
authors.lastname: Jia
authors.forename: Dongfang
authors.initials: D
authors.lastname: Yang
authors.forename: Xiangna
authors.initials: X
authors.lastname: Han
authors.forename: Junhui
authors.initials: J
authors.lastname: Cai
authors.forename: Haiying
authors.initials: H
authors.lastname: Liu
authors.forename: Weiwei
authors.initials: W
authors.lastname: He
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D001205:Ascorbic Acid / Q000737:chemistry; D015374:Biosensing Techniques; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D003124:Colorimetry; D004791:Enzyme Inhibitors / Q000737:chemistry; D005707:Gallic Acid / Q000737:chemistry; D005947:Glucose / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D009195:Peroxidase / Q000737:chemistry*; D013634:Tannins / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D010087:Oxides; D013634:Tannins; D003035:Cobalt; D005707:Gallic Acid; D006861:Hydrogen Peroxide; D009195:Peroxidase; D005947:Glucose; D001205:Ascorbic Acid; D010100:Oxygen; C060728:cobalt oxide