Preparation and Optimization of Fluorescent Thin Films of Rosamine-SiO(2)/TiO(2) Composites for NO(2) Sensing

The incorporation of a prototypical rosamine fluorescent dye from organic solutions into transparent and microstructured columnar TiO [Formula: see text] and SiO [Formula: see text] (MO [Formula: see text]) thin films, prepared by evaporation at glancing angles (GAPVD), was evaluated. The aggregation of the adsorbed molecules, the infiltration efficiency and the adsorption kinetics were studied by means of UV-Vis absorption and fluorescence spectroscopies. Specifically, the infiltration equilibrium as well as the kinetic of adsorption of the emitting dye has been described by a Langmuir type adsorption isotherm and a [Formula: see text] second order kinetic model, respectively. The anchoring mechanism of the rosamine to the MO [Formula: see text] matrix has been revealed by specular reflectance Fourier transform infrared spectroscopy and infiltration from aqueous solutions at different pH values. Finally, the sensing performance towards NO [Formula: see text] gas of optimized films has been assessed by following the changes of its fluorescence intensity revealing that the so-selected device exhibited improved sensing response compared to similar hybrid films reported in the literature.