Surface Modification of Co 3 O 4 Nanoplates as Efficient Peroxidase Nanozymes for Biosensing Application

• Published in: ACS applied bio materials Vol. 4; no. 4; pp. 3443 - 3452
• Main Authors: Huo, Jianzhong, Hao, Jinyu, Mu, Jianshuai, Wang, Yan
• Format: Journal Article
• Language: English
• Published: United States 19.04.2021
• Subjects: Biocompatible Materials - chemistry; Biosensing Techniques; Cobalt - chemistry; Hydrogen Peroxide - analysis; Materials Testing; Molecular Structure; Nanostructures - chemistry; Oxides - chemistry; Particle Size; Peroxidase - chemistry; Peroxidase - metabolism; Surface Properties; nanozymes; mimetic peroxidase; H2O2 sensor; surface modification; Co3O4 nanoplates
• ISSN: 2576-6422; 2576-6422
• DOI: 10.1021/acsabm.1c00017

Nanomaterial-based mimetic enzymes, called nanozymes, received more and more attention in recent decades; however, their lack of biocompatibility limited the biomedical applications, which could be solved by surface modification. In this work, the Co O nanoplates were modified by different functional groups, including the amino group, carboxyl group, hydroxyl group, and sulfhydryl group (NH -Co O , COOH-Co O , OH-Co O , and SH-Co O ). And the modified Co O nanoplates were characterized by XRD, SEM, TEM, XPS, FTIR, TG, and the Zeta potential, verifying the successful modification of different functional groups. Their mimetic peroxidase properties and kinetics process were further studied and showed that the order of their catalytic activities was as follows: NH -Co O > SH-Co O > COOH-Co O > pure Co O > OH-Co O , and the catalysis of modified Co O nanozymes all followed Michaelis-Menten kinetics. The results indicated that the different functional groups changed their electron transfer ability, and further affected their catalytic activity. H O detection was selected as an application model system to evaluate the modified Co O nanozymes. Compared with other Co O nanozymes, a wider linear range from 0.01 to 40 mmol L and a lower detection limit of 1.5 μmol L was constructed with NH -Co O nanozymes. The results suggested that surface modification by functional groups was a robust strategy to improve the application of Co O nanozymes. The enhanced catalytic activity and good biocompatibility of modified Co O nanozymes provided valuable materials for the relative application, such as medical detection and antioxidation.