Rapid controlled synthesis of gold–platinum nanorods with excellent photothermal properties under 808 nm excitation

[摘要] Noble metal nanomaterials are particularly suitable as photothermal transduction agents (PTAs) with high photothermal conversionefficiency (PCE) due to local surface plasmon resonance (LSPR). Studies on different gold–platinum (Au–Pt) bimetal nanoparticles exhibiting the LSPR effect have provided a new idea for the synthesis of excellent PTAs. But there is no simple and scalablemethod for the controllable synthesis of Au–Pt nanoparticles with adjustable LSPR wavelength range. In this work, the effects ofAg+ and K2PtCl4 on the deposition of Pt on the surface of gold nanorods (AuNRs) were investigated. A fast, precise, and controlled synthesis of dumbbell-like Pt-coated AuNRs (Au@Pt NRs) under mild conditions is proposed. The synthesized Au@Pt NRshave a longitudinal LSPR wavelength of 812 nm, which is very close to a common laser wavelength of 808 nm. The Au@Pt NRsexhibit excellent photothermal properties when irradiated with a laser. The temperature increased by more than 36 °C after irradiation for 10 min, with a PCE of about 78.77%, which is much higher than that of AuNRs (57.33%). In addition, even after four on/off cycles, the Au@Pt NRs are able to maintain the photothermal properties and retain their optical properties, indicating that theyhave excellent photothermal stability and reusability.

[学科分类] 环境监测和分析

[关键词] AuNRs;local surface plasmon resonance (LSPR);photothermalconversion efficiency;photothermal transduction agents;platinum