AuPeroxidase nanozymes: Promises and applications in biosensing

Nanozymes or enzyme mimetic nanostructures possessing intrinsic catalytic activity circumvent various limitations of natural enzymes and hence have emerged as their promising alternative. Gold nanostructures or their hybrids with other metals are popular nanozymes because of their easy synthesis, facile surface modifications, stability, and possessing excellent peroxidase activity. Since 2004, when peroxidase activity was reported for the first time in gold nanoparticles, numerous researches have been done on assessing their peroxidase activity with changing morphology, and making hybrid with different metals. Past few years have witnessed a boom in the use of peroxidase gold nanozyme in biosensing applications. To follow the pace of gold peroxidase (Auperoxidase) nanozyme based biosensing strategies, it is apt to meticulously review this subject. Therefore, the present review covers research publications since 2013 and intends to understand the peroxidase activity in gold nanozymes with variable physico-chemical factors. It further dwells into the proposed mechanisms for the intrinsic peroxidase activity in gold nanozymes. With this review, we intend to present an eagle eye's view of various ways in which gold nanozymes have been used in detection or sensing of diverse analytes such as clinical biomarkers, environmental or food contaminants, antibiotics etc.