Enhanced the performance of fluorescence gas sensor of porphyrin dye by using TiO2 nanoparticles

Abstract

Fluorescence gas sensor was developed to identify the presence of volatile organic compounds by using porphyrin dye thin film. The porphyrin dye used was iron (III) mesotetraphenylporphine chloride. The porphyrin thin film was deposited on quartz substrate using self-assembly through dip coating technique. The sensing properties of the thin films toward volatile organic compounds; ethanol, acetone and 2-propanol were studied using luminescence spectrometer. In presence of air and volatile organic compounds, thin films produced different emission spectra and ease for chemical identification process. To improved the sensing performance, TiO2 nanoparticles colloid were prepared, coated with porphyrin dye and deposited as thin film. It was found that the thin film of TiO2 nanoparticles coated with porphyrin dye has more intensive interaction toward volatile organic compounds than porphyrin thin film, and improved the selective property. This may be due to the nanostructured thin film provided more surface area for dye molecules to react with VOCs. © 2008 Trans Tech Publications, Switzerland.