Porous nanoarchitectures based on TiO2 aerogels and Au particles as potential SERS sensor for monitoring of water quality

Encouraged by the environment friendly character of TiO2 and the well-known affinity of a large variety of molecules to bind to the gold nanostructures surface we obtained novel porous nanoarchitectures based on TiO2 aerogel and Au colloidal particles and tested their capability to detect contaminant species adsorbed from an aqueous solution on metallic nanoparticles surface. The efficiency of the composites prepared by various methods to detect pollutants from water by surface-enhanced Raman spectroscopy (SERS) was established by using thioacetamide, crystal violet and rhodamine 6G as test molecules and comparatively discussed. The lowest detectable concentrations were found to depend on the sample preparation method and the pollutant species type and were determined to be of around 10(-2) M for thioacetamide and in the range between 10(-5) and 10(-7) M for dye molecules off and under resonant excitation, respectively. The obtained results show the real potential of the prepared porous composites for further use in the development of new SERS-based sensors for monitoring of water quality. (C) 2008 Elsevier B.V. All rights reserved.