Bimetallic synergistic Pd-Pt icosahedra as highly active peroxidase-like mimics for colorimetric analysis

Thanks to the synergistic effect, the bimetallic catalysts show better catalytic activity than the single metal catalysts and become a focus of research in heterogeneous catalysis. In this study, we successfully prepared Pd-Pt icosahedra which show high peroxidase-like activity under the synergistic effects of Pd and Pt. Vmax of the Pd-Pt icosahedra was significantly enhanced by 1.66 times for 3,3',5,5'-tetramethylbenzidine (TMB) as the substrate and 1.23 times for H2O2 as the substrate, compared to that of the Pd icosahedra alone. By harnessing the superior peroxidase-like activity of Pd-Pt icosahedra, we successfully utilized Pd-Pt icosahedral nanozymes in various biological analyses based on colorimetry. In most cases, using a Pd-Pt icosahedra/H2O2/TMB system, glucose, glutathione (GSH), acid phosphatase (ACP), and alkaline phosphatase (ALP) were detected over a wide range of 0.05∼0.20 mM, 0∼20 mM, 0∼10 U/L and 0∼12 U/L. In this study, we prepared a novel bimetallic nanozyme that exhibited excellent peroxidase-like activity owing to the bimetallic synergistic effect, thus demonstrating the promising potential of Pd-Pt icosahedra in the field of bioanalysis.