Ultrasmall Cu2O@His with laccase- and catechol oxidase-like activity: Applications in phenolic drug identification and degradation

Nanozymes constitute a category of nanomaterials exhibiting the potential to replace natural enzymes. Although many types of nanozymes have been widely reported in different fields, fabricating nanozymes with ultrasmall dimensions and expanding their applications is still a great challenge. In this study, we present a cost-effective, one-step methodology for producing ultrasmall Cu2O@His. Comparative to natural laccases, Cu2O@His demonstrates remarkable catalytic capabilities in phenolic catalysis, alongside robust stability and economic viability. Therefore, some potential applications of Cu2O@His as an alternative to natural laccase were explored. Cu2O@His has been utilized not only for the detection of epinephrine but also for the degradation of tetracycline antibiotics. In addition, four kinds of TCs were successfully distinguished by principal component analysis. This work provides new ideas and methods for the development of nanozymes with ultrasmall dimensions and for the study of applications of laccase-like activity.