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

作者：Ermakov Victor A^*; Jimenez Villar Ernesto^*; Clemente da Silva Filho Jose Maria; Yassitepe Emre; Vardhan Mogili Naga Vishnu; Iikawa Fernando; de Sa Gilberto Fernandes; Cesar Carlos Lenz; Marquest Francisco Chagas

来源：Langmuir, 2017, 33(9): 2257-2262.

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.

• 出版日期2017-3-7