Studies of different methods of synthesis of gold nanoparticles in order to immobilization in LbL films for application in sensors of heavy metals

• Grant number: 13/15755-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2013
• End date: July 20, 2014
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Marystela Ferreira
• Grantee: Clara Raíssa Steinberg Ostapenko
• Host Institution: Centro de Ciências e Tecnologias para a Sustentabilidade (CCTS). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil

Abstract

The project aims to obtain gold nanoparticles (AuNPs) via different routes of synthesis in aqueous medium, which will be stabilized with different thiols, such as 2-mercaptoetano sodium and 11-mercaptoundecanoic and even the use of Poly (allylamine hydrochloride) (PAH) to aid in dispersion. The syntheses are also performed with different reducing agents, especially sodium borohydride and sodium citrate in order to verify AuNPs order to further stabilize the immobilization of self-assembled layers of these substrates solids. The self-assembled films are fabricated by the "layer by layer" (LbL) technique using polyelectrolytes of opposite charge nanoparticles, such as poly (vinyl sulfate) (PVS) and poly (ethyleneimine) (PEI). The AuNPs are still immobilized by intercalation of nanoparticles of clay montmorillonite (MMT-Na+). These self-assembled films containing MMT-Na +/AuNPs and are characterized individually and together, by spectrophotometry in the ultraviolet visible (UV-vis) in order to determine a best architecture for the films. Determine the best architecture for the LbL films of AuNPs and MMT-Na +, these will be deposited ITO to verify electrochemical activity of the film acting as a sensor of heavy metals. The sensors will be evaluated by electrochemical measurements of cyclic voltammetry (CV).