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

Author(s)

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

• Document type: Journal article
• Source: Langmuir; v. 33, n. 9, p. 2257-2262, MAR 7 2017.
• Web of Science Citations: 17

Abstract

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. (AU)

• FAPESP's process: 05/51689-2 - Optics and Photonics Research Center at UNICAMP
• Grantee: Hugo Luis Fragnito
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 13/26385-6 - Development and study of nanoparticles that generates multiple excitons and plasmonic effects applied for solar cells
• Grantee: Viktor Ermakov
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 11/51959-0 - Biology of neoplastic diseases of bone marrow
• Grantee: Sara Teresinha Olalla Saad
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 12/10127-5 - Research and development of nanostructured materials for electronic and surface physics applications
• Grantee: Fernando Alvarez
• Support Opportunities: Research Projects - Thematic Grants