Lucian Baia
Babes-Bolyai University, Romania
Title: Highly porous based nanocomposites designed for ultrasensitive detection of environmental pollutants
Biography
Biography: Lucian Baia
Abstract
Aerogels are highly porous materials with a low density, large open pores, and a high inner surface area produced via sol-gel process followed by supercritical drying. Their unique morphological characteristics like pore volume, pore size distribution and connectivity, make them suitable for sensor applications. Our research activity in the last period was focused on designing such uniqe porous structures for improving their capability for ultrasensitive detection of environmental pollutants. In this respect, the first approach consisted in designing TiO2 aerogel-Au/Ag nanoparticles based materials for efficient detection by using Surface-Enhanced Raman Scattering (SERS), taking into consideration the great enhancement of the Raman signal that occurs after positioning a pollutant molecule on Au/Ag nanoscale-roughed surfaces, or in their proximity. The greatest performances related to the mentioned functionalities were acquired for the porous composites obtained by impregnating the titania gel with Au/Ag nanoparticles followed by supercritical drying, and the lowest detectable concentrations by SERS varied between 10-2 and 10-10 M, depending on the synthesis method, pollutant species and the excitation type, i.e. off and under resonant condition. The second approach is related to the obtaining of electrodes based on Bi doped carbon aerogels and xerogels, incorporated in a matrix of chitosan, and deposited on glassy carbon, for the ultrasensitive voltammetric detection of heavy metals like Pb(II) and Cd(II), and pharmaceuticals compounds. For this approach the detection limits were found to be between 10-8 and 10-13 M, depending on the pollutant type.