Synthesis and electrochemical characterization of piers substrates for the detection of chemicals of environmental interest

• Grant number: 22/04412-0
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: June 30, 2022
• End date: November 30, 2022
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Paola Corio
• Grantee: Douglas dos Santos Lopes
• Supervisor: Alexandre G. Brolo
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of Victoria (UVic), Canada
• Associated to the scholarship: 19/03371-6 - Investigation of the SERS and catalytic activity of plasmonic nanostructures in the degradation of organochlorine and organophosphorus pesticides, BP.DD

Abstract

Surface enhanced Raman spectroscopy (SERS) has established itself as an important analytical tool for the detection of chemical and biological analytes of interest. The implementation of SERS has been conditioned to the preparation of Ag and Au nanostructured substrates, which allow the acquisition of characteristic vibrational bands due to the high concentration of the incident field on the metallic surface to form an enhanced and highly localized local field. Recently, however, semiconductor materials have been explored as a way to broaden the material scope of SERS substrates. However, the enhancement mechanism based on non-plasmonic effects makes the practical application of semiconductors as SERS-active substrates quite restricted. Among other implemented strategies, the photoinduced enhanced Raman spectroscopy (PIERS) technique was demonstrated to be able to significantly enhance the Raman scattering by up to 10 orders of magnitude when compared to the traditional implementation of SERS. PIERS substrates are prepared from junctions between semiconductors or insulators and plasmonic materials and are excited with high energy irradiation preceding Raman analysis. The present project aims at the preparation of PIERS substrates and the consequent optimization of the process of detecting chemical analytes of environmental interest, systematically evaluating the mechanisms of intensification operating in PIERS. The studies will also be focused on investigating the electrochemical behavior of PIERS substrates as a way to modulate charge transfer processes between metal and semiconductor. (AU)