Sensors based on thin films of organic materials: development and film/analyte molecular interactions

• Grant number: 12/09053-7
• Support Opportunities: Regular Research Grants
• Duration: August 01, 2012 - July 31, 2014
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Carlos José Leopoldo Constantino
• Grantee: Carlos José Leopoldo Constantino
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

This Regular Research Project aims to give continuity to the works have been carried out through the previous research projects FAPESP 01/10520-4 (2002 - 2006), FAPESP 06/51039-0 (2006 - 2008) and FAPESP 09/16021-1 (2010 - 2012). It is also a basis for the research projects developed by undergrad, grad, PhD and postdoc students under my coordination, in addition to my CNPq fellowship (PQ - 1d). The focus of this Regular Research Project is in the study of molecular interactions between thin films of organic materials and analytes of interest with two main objectives: i) understand the mechanisms of interaction film/analyte, which, in the case of lipids applied as mimetic systems of biological membranes has an interest itself; ii) develop electronic tongue type sensors using the materials that in (i) shown to be more sensitive to certain analytes. The interactions are investigated using optical spectroscopy (Raman scattering and SERS, absorption in the UV-Vis and FTIR), microscopy (optics, SEM and AFM) and electric measurements (DC, impedance and differential cyclic). The sensing units are fabricated by depositing thin films (nanometer thickness) of organic materials onto interdigitated electrodes (for impedance spectroscopy) or ITO (for cyclic voltammetry). These materials include basically perylene tetracarboxilic derivatives, phthalocyanines, Schiff base complexes, lignins, and mainly cationic, anionic and zwitterionic lipids, which are deposited using layer-by-layer (LbL), Langmuir-Blodgett (LB) and vacuum thermal evaporation (PVD-physical vapour deposition), techniques, depending on the material. The analytes are water-soluble compounds such as salts of heavy metals, pesticides and pharmaceuticals. (AU)