Advanced Pulsed Laser Ablation in Liquid Technique to Fabricate Composite Si/Au Nanoparticles for Biophotonics

Silicon nanoparticles decorated with small gold (Au) inclusions are of potential interest as agents for efficient photothermal conversion in tumor hyperthermia applications. In this work, we present the technology for synthesizing a suspension of composite silicon–gold (Si/Au) nanoparticles with a core-satellite type morphology. They are quasi-spherical with the mean diameter of up to 75 nm and relative size dispersion not exceeding 32%, while the decorating Au inclusions range in size of 5–15 nm. Fabrication is implemented through a dual-stage laser ablation technique employing a porous silicon target, ethanol (first stage) and a water-ethanol solution with chloroauric acid HAuCl4 (second stage) as buffer media. The fabricated composite Si/Au nanoparticles possess a high degree of crystallinity and exhibit moderate colloidal stability in water.