New SERS based sensors for detection of water chemical pollutants


Abstract

The aim of this project is to obtain new SERS based sensors for water quality control by using highly porous composites based on TiO2 aerogels and Au or Ag nanoparticles of different dimensions and concentrations. The composites capacity of sensing chemical pollutants from water will be tested by SERS and SERRS techniques. Thus, the samples ability to detect very small concentrations of pollutants adsorbed on Au or Ag nanoparticles surface will be evaluated, by taking into account the advantage of the porous structure that allows the pollutant diffusion and consequently, recording of the Raman signal from a volume, where the number of adsorbed species is higher in comparison with the case when a conventional SERS substrat is employed. The optimization procedure used for the obtaining of the porous nanocomposites by using different quantities of noble metal nanoparticles of various dimensions has as main goal the maximization of their detection performances ensuring thus the selectivity of the porous material on the pollutant type. The porous nanocomposites with the greatest standard chemical pollutants sensing eficiency will be deposited on solid substrates and will be analyzed togheter with the obtained films from a morphological (pores volume distribution and their surface area, SEM, TEM, UV-VIS) and structural (Raman and IR spectroscopy, XPS) point of view. The porous films capacity to detect standard chemical pollutants and contaminants from industrial and medical wastewaters will be evaluated. The synthesis, characterization and testing of these porous nanoarchitectures would certainly contribute to the development of complex devices designed to monitor the water quality from various environments.