Selective detection of organic vapors using TiO2 nanotubes based single sensor at room temperature

The present study demonstrates a new measurement technique for the selective detection of multiple volatile organic compounds (VOCs) at room temperature (300 K) by using a single sensor. Electrochemically grown TiO2 nanotubes based sandwich-structured device was fabricated to realize the selectivity technique. The proposed method of selective detection of VOCs involved simultaneous measurement of both resistive and capacitive responses of the sensor upon exposure to different VOCs. By using these two types of responses, an algorithm was developed to formulate a new quantity known as 'selectivity constant' (S) for each VOC. This quantity exhibited a unique and concentration independent numerical value for different VOCs. The developed algorithm was tested successfully to identify different types of VOCs like methanol, ethanol, acetone and 2-propanol and their concentration.