Tests in controlled atmosphere on new optical gas sensing layers based on TiO2/metal-phthalocyanines hybrid system

Chemical sensors based on surface plasmon resonance (SPR) measurements have been proposed in various applications ranging from biomedical and environmental monitoring to industrial process control. It is widely gaining recognition as a valuable tool to investigate gas sensing interactions. In this work, surface plasmon resonance studies in angular modulation have been used to characterise response in the presence of NO2 toxic gas of thin TiO2 porous films containing different types of metal-phthalocyanines. The hybrid thin films were prepared using sol–gel technique. Low temperature annealing of the films (80 °C) ensured the formation of microporous TiO2 backbone and the preservation of phthalocyanine. Optical parameters of the active layers in dry air were calculated by using the SPR measurements and information about their variation in the presence of different concentrations of toxic gas was obtained.