Recent advances of peroxidase-active nanozymes in electrochemical immunoassays

Abstract

A new type of nanomaterial with peroxidase activity (peroxidase-active nanozyme) has been widely used in the design of electrochemical immunosensors. Due to the high and tunable catalytic activity, ease of modification, large surface area, and low cost, they have gradually emerged as alternatives to natural enzymes. To date, a variety of peroxidase-active nanozymes have been reported, including metal–organic frameworks (MOFs), transition metal-based oxygenated compounds (oxides, peroxides, and hydroxides), noble metal nanoparticles, Prussian blue and other transition metal-containing biomolecules, which have been successfully applied to the construction of electrochemical immunoprobes and substrates. Herein, we briefly summarize the research progress on peroxidase-active nanozymes that have been successfully applied to electrochemical immunosensors in recent years, including their synthesis, the assembly steps of the constructed sensors, and the working mechanism. We also discuss some problems encountered in the application of these nanozymes in electrochemical immunosensors and provide some possible strategies to address these limitations. We hope that this review will be helpful for researchers to understand and select such nanozymes, and it will also promote the development of novel electrochemical immunosensors with excellent performance in the future.