In this PhD project, ultrathin films (nanometers of thickness) of phospholipids will be manufactured using the Layer-by-Layer (LbL) and Langmuir-Blodgett (LB) techniques, in order to obtain films with different molecular architectures. Anionic and zwitterionic phospholipids will be employed and the main objectives are: i) explore the effectiveness of these different molecular architectures for detecting xanthenes derivatives in dilute solutions (environmental aspect); ii) investigate the chemical interactions between xanthenes and thin films of phospholipids, as mimetic systems of biological membranes (pharmacological aspects). The thin films are deposited onto Pt interdigitated electrodes composing sensing units to be characterized via impedance spectroscopy (detection) by dipping them into aqueous solutions containing different xanthenes concentrations, being phospholipids the elements responsible for the signal transduction. The Raman scattering and surface-enhanced Raman scattering (SERS) techniques will be used as the main tool for analysis of xanthene/phospholipid interactions, complemented by infrared absorption spectroscopy (FTIR). The growth of LbL and LB films will be monitored via ultraviolet-visible absorption spectroscopy (UV-Vis) and micro-crystal quartz balance (QCM). The micrometer-scale morphology will be determined via micro-Raman technique, at nanometer-scale via atomic force microscopy (AFM) and scanning electron microscopy with field emission (FEG-SEM). This PhD project is designed within the research line of the FAPESP Research Grant 2009/16021-1 developed at DFQB FCT / UNESP and will be co-supervised by Professor Dr. Wilker Caetano from UEM/Maringá, whose expertise is molecular biophysics. It will also count with the collaboration of professors Drs. Antonio Riul Jr. (UFSCAR / Sorocaba), specialist in sensors for liquid medium ("electronic tongue") and Noboru Hioka (UEM / Maringá), specialist in molecular spectroscopy and photochemistry.
News published in Agência FAPESP Newsletter about the scholarship: