Size Control of Silver-Core/Silica-Shell Nanoparticles Fabricated by Laser-Ablation-Assisted Chemical Reduction

• Published in: Langmuir 2017-03, Vol.33 (9), p.2257-2262
• Main Authors: Ermakov, Victor A, Jimenez-Villar, Ernesto, Silva Filho, José Maria Clemente da, Yassitepe, Emre, Mogili, Naga Vishnu Vardhan, Iikawa, Fernando, de Sá, Gilberto Fernandes, Cesar, Carlos Lenz, Marques, Francisco Chagas
• Format: Article
• Language: English
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/acs.langmuir.6b04308

Aqueous colloidal silver nanoparticles have substantial potential in biological application as markers and antibacterial agents and in surface-enhanced Raman spectroscopy applications. A simple method of fabrication and encapsulation into an inert shell is of great importance today to make their use ubiquitous. Here we show that colloids of silver-core/silica-shell nanoparticles can be easily fabricated by a laser-ablation-assisted chemical reduction method and their sizes can be tuned in the range of 2.5 to 6.3 nm by simply choosing a proper water–ethanol proportion. The produced silver nanoparticles possess a porous amorphous silica shell that increases the inertness and stability of colloids, which decreases their toxicity compared with those without silica. The presence of a thin 2 to 3 nm silica shell was proved by EDX mapping. The small sizes of nanoparticles achieved by this method were analyzed using optical techniques, and they show typical photoluminescence in the UV–vis range that shifts toward higher energies with decreasing size.