Synthesis of Pt Nanoparticles Encapsulated inside Dendrimers As Tunable Oxidase Mimics for Turn-on Fluorescent Sensing of Oxygen

Abstract

Here, we present the controllable synthesis of dendrimer-encapsulated Pt nanoparticles (Pt DENs) utilizing repetitively coupled chemical reduction and galvanic exchange reactions. This facile method allowed controllable synthesis of the Pt DENs with fair homogeneity in size and composition. In particular, in contrast to the conventional dendrimer-templating methods, the proposed synthesis method allowed substantial increase in the applicable number of Pt atoms up to 1320 in Pt DENs without being limited by the fixed number of complexation sites for the Pt2+ precursor ions in dendrimers. We also present a detailed investigation on the oxidase-mimetic activity of the Pt DENs for catalytic oxidation of Amplex Red to resorufin with O2. Importantly, after clarifying intrinsic oxidase-mimetic activity of the Pt DENs, we disclosed that the Pt DENs’ oxidase-mimetic activity was tailorable for the oxidation of Amplex Red to resorufin especially with fine-tuning of the Pt2+/dendrimer ratios by using the proposed synthesis method.