Tuning the core size and the silica shell of metallic nanoparticles for effectiveness surface-enhanced phenomena

• Grant number: 15/03143-2
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: July 01, 2015
• End date: June 30, 2016
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Carlos José Leopoldo Constantino
• Grantee: Sabrina Aléssio Camacho
• Supervisor: Alexandre G. Brolo
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil
• Institution abroad: University of Victoria (UVic), Canada
• Associated to the scholarship: 13/01897-4 - Synthesis of gold nanoparticles for enhancement of Raman scattering (SERS) and fluorescence (SEF) targeting sensory applications, BP.DR

Abstract

Shell-isolated nanoparticles (SHINs) are metallic nanostructures coated with a silica shell and applied to Raman and fluorescence signal amplification. SHINs provide a reliable, portable and efficient substrate for optical enhancement leading to surface-enhanced spectroscopy. For nanoparticles with ultrathin coating (2-4 nm), the shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) is achieved. As the thickness of the coating increases (5-20 nm), the shell-isolated nanoparticle-enhanced fluorescence (SHINEF) takes place. In this research project for an internship abroad, gold and silver nanoparticles (AuNPs and AgNPs) coated with a silica shell will be incorporated to nanostructured films and solutions of target molecules to obtain SHINERS and/or SHINEF effects. The aim is evaluate the influence of core size and coating thickness on the optical properties of the nanoparticles, as scattering and emission signal amplification. For this purpose, the nanoparticles will be synthesized with distinct core sizes and coating thicknesses, tuning these characteristics for maximum SHINERS and SHINEF enhancement. Complementarily, the SHINs will be incorporated into surfaces which have very low concentrations of residual contaminants (ex. pesticides present in the peel of fruits and vegetables) for sensing applications. (AU)