Mechanisms of colloidal aggregation induced by carbendazim: a study via transmission electron microscopy (TEM)

• Grant number: 23/05423-9
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: July 01, 2023
• End date: July 31, 2023
• Field of knowledge: Engineering - Materials and Metallurgical Engineering
• Principal Investigator: Carlos José Leopoldo Constantino
• Grantee: Isabela Bianchi Carvalho
• Supervisor: Santiago Sanchez-Cortes
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil
• Institution abroad: Centro de Física Miguel Antonio Catalán (CFMAC), Spain
• Associated to the scholarship: 21/02746-6 - Surface-enhanced Raman Scattering (SERS): pesticide detection and adsorption mechanism, BP.IC

Abstract

The undergraduate research project in progress in Brazil has the main focus on detection of carbendazim (a fungicide) via surface-enhanced Raman scattering (SERS) technique using Ag colloid, being evaluated the effect of sample preparation (standard addition method - SAM and external standard method - ESM) on the SERS signal. In this meaning, the level of aggregation of nanoparticles in colloids is one factor that influences the reproducibility of the intensity of the SERS signal. The formation of aggregates induced by the addition of analytes to colloid can occur by two mechanisms: diffusion-limited colloid aggregation (DLCA) and reaction-limited colloid aggregation (RLCA). The chemical structure of the analytes and their interaction with the nanoparticle surface can influence these mechanisms. Thus, this project aims to investigate the different levels of aggregation (mechanism and morphology) of nanoparticles induced by the addition of carbendazim. A systematic study will be conducted to determine the aggregation mechanism induced by each sample preparation method in the colloidal system via transmission electron microscopy (TEM). The project will be carried out in Spain supervised by Dr. Santiago Sanchez Cortés, who has extensive experience in the synthesis of colloidal systems (metal nanoparticles), using the SERS technique in applications with various analytes. Our research group has had a fruitful collaboration with the researcher Santiago for more than 10 years. (AU)