Phospholipids are a class of materials widely applied as mimetic system of the cell membrane in interaction studies with several analytes. Thus, the use of phospholipids could contribute to a better detection of herbicides and other toxic compounds in sensing applications, considering the susceptibility of living organisms by these compounds. In addition of detection, it may also allow to investigate the effect of these compounds on the wall of cell membrane, having lipids as biomimetic models. This PhD project includes both aspects. Will be investigated the interaction of atrazine, ametrina and prometryn herbicides with the phospholipid dipalmitoyl phosphatidylcholine (DPPC) as a biological membrane model. The interaction of phospholipid with the herbicides will be studied by means of two systems: i) DPPC Langmuir films characterized by surface pressure isotherms vs. mean molecular area (À-A isotherms) and infrared spectroscopy with polarization modulation (PM-IRRAS) and ii) giant unilamellar vesicles (GUVs) of DPPC electroformed and characterized by confocal microscopy/Fluorescence. The other aspect will address the detection of herbicides by means of surface-enhanced Raman scattering spectroscopy (SERS) in colloidal system of Ag nanoparticles (AgNPs) in order to obtain analytical curves from the adsorption of the herbicide onto the surface of AgNPs. In this case the strategy is to dilute the pesticides in AgNPs colloidal systems in the presence and absence of DPPC. The combination of both materials (AgNPs and DPPC) may lead to desirable properties improving the sensitivity for detection, quantitation and interaction of specific chemical species. This project is part of the Thematic Project FAPESP 2013/14262-7 entitled "Nanostructured films of biological interest materials".
News published in Agência FAPESP Newsletter about the scholarship: