Synthesis of Gold-Platinum Core-Shell Nanoparticles Assembled on a Silica Template and Their Peroxidase Nanozyme Properties

Abstract

Bimetallic nanoparticles are important materials for synthesizing multifunctional nanozymes. A technique for preparing gold-platinum nanoparticles (NPs) on a silica core template (SiO2@Au@Pt) using seed-mediated growth is reported in this study. The SiO2@Au@Pt exhibits peroxidase-like nanozyme activity has several advantages over gold assembled silica core templates (SiO2@Au@Au), such as stability and catalytic performance. The maximum reaction velocity (Vmax) and the Michaelis–Menten constants (Km) were and 2.1 × 10−10 M−1∙s−1 and 417 µM, respectively. Factors affecting the peroxidase activity, including the quantity of NPs, solution pH, reaction time, and concentration of tetramethyl benzidine, are also investigated in this study. The optimization of SiO2@Au@Pt NPs for H2O2 detection obtained in 0.5 mM TMB; using 5 µg SiO2@Au@Pt, at pH 4.0 for 15 min incubation. H2O2 can be detected in the dynamic liner range of 1.0 to 100 mM with the detection limit of 1.0 mM. This study presents a novel method for controlling the properties of bimetallic NPs assembled on a silica template and increases the understanding of the activity and potential applications of highly efficient multifunctional NP-based nanozymes.

Silica Encapsulation of Hydrophobic Optical NP-Embedded Silica Particles with Trimethoxy(2-Phenylethyl)silane

“…Finally, the silica shell provides flexibility for surface modification. Silanol groups can easily react with various silanol precursors with functional groups, such as amine or thiol groups; therefore, various functional groups like amine or thiol groups can be introduced with other silylether-containing compounds, such as 3-aminopropyl triethoxysilane (APTES), 3-chloropropyl trimethoxysilane (CPTMS), 3-glycydoxypropyl trimethoxysilane (GPTS), or 3-mercaptopropyl trimethoxysilane (MPTS) [ 12 , 13 , 14 , 15 ].…”

Highly catalytic and stable Au@AuPt nanoparticles for visual and quantitative detection of E. coli O157:H7

“…19,20 Pt-based nanoparticles show excellent water solubility and superb peroxidase-like activity, although their stability is poor due to susceptibility to aggregation and active site poisoning. [21][22][23] An Au-Pt alloyed nanozyme was proposed due to its enhanced catalytic ability and robust stability. Combining Au and Pt nanoparticles results in a synergistic effect that enhances catalytic activity by facilitating electron transfer while maintaining excellent stability.…”

“…Pt exhibited outstanding HRP-like activity, but it may suffer from instability due to the absorption of intermediates or active site poisoning. 21,22,31,32 Nevertheless, the presence of Au could enhance the stability and boost the catalytic activity of Pt through synergistic electronic effects. 33,34 Therefore, the varying ratios of Au and Pt could significantly influence the catalytic activity of Au@AuPtNPs.…”