Understanding the oxidoreductase behaviour of Platinum Nanoparticles

Nanozymes are nanomaterials that display catalytic activities similar to those of natural enzymes. Recently they attracted great interest in the scientific community because of their advantages compared to natural enzymes, such as higher stability, a wider pH operational range and easier storability. It is known that metallic and metal-oxide nanoparticles (NPs) possess different enzyme-like activities1 such as peroxidase (POD), catalase (CAT) and oxidase (OX). These activities are affected by NPs' chemical and physical features; thanks to their versatility, nanozymes have been exploited in a wide range of applications such as sensing/diagnostic, cancer treatments and organic pollutants remediation in wastewaters. Despite the continuously increasing number of applications, there is much yet to reveal concerning nanozymes’ activities and how their catalytic mechanism are affected by environmental factors such as pH, temperature, buffer composition and reagents concentration. Platinum NPs (PtNPs) are, currently the rising stars for oxidoreductase-like activities. We investigated how the environmental factors, mentioned above, can modulate CAT, OX and POD-like activities of PtNPs gaining important insights regarding the mechanisms involved in their catalytic properties. This study is fundamental to provide useful information for the development of applications based on Pt nanozymes. Furthermore, the catalytic properties of PtNPs are being compared with those of other, frequently used, nanozymes to help choosing the best nanozyme for each application.