Chemical sensor based on titanium dioxide thick film: Enhancement of selectivity by surface coating

Titanium dioxide chemical sensor working with AC voltage can be used to discern individual chemical compound, using a single detector. Two different types of molecules, i.e., alcohols and benzenes were used as the adsorbent on the surface of the sensor. Results showed that three parameters that were used to trace a single molecule, were also helpful to determine the existence of mixed gases and their ratio of mixture. It was also found that when the sensor surface was coated with a bilayer of polyion complex, it enhanced the selectivity of the sensor. In this case benzene molecules showed vivid response compared to the alcohols. (C) 1999 Elsevier Science B.V. All rights reserved.