Preparation of novel hybrid sensing materials: porphyrin doped tin dioxide thin films.

Hybrid CoTPP-SnO2 thin films have been obtained by the sol-gel approach coupled with spin coating technique. These films have been deposited onto interdigital electrodes and their performances as chemical sensors have been measured towards the detection of methanol vapors. These CoTPP-SnO2 sensors showed fast and reversible responses towards different concentrations of methanol and best results were obtained at 250 degrees C working temperature, while a sharp decrease was observed at higher temperatures. These results are attributed to the well known catalytic activity of metalloporphyrins, which is not thermally decomposed at 250 degrees C, as confirmed by optical measurements.