Pd/TiO2 NT/Ti Metal-Insulator-Metal Devices as a Reliable Detector of Degradation of Potato

Abstract

TiO2 nanotube (NT) based Metal-Insulator-Metal (MIM) sensor device was fabricated to detect the Volatile Organic Compounds (VOCs) emitted from the bacteria (Erwina carotovora) infected rotten potato tubers with an aim of timely detection of the degradation of potato during storage. The concentrations of the principal components of emerged VOCs (ethanol, acetone, 2-propanol, 2-butanone) were used as the potential markers for distinguishing the degraded potato from the fresh ones. The sensor response towards fresh, 7 days infected and 14 days infected potatoes (each of 100 gm) was found to be 15%, 45% and 73%, respectively at 75 °C. Long term stability of the sensor was investigated for one month and repeatability of the sensor was also tested for 40 test cycles at the operating temperature of 27 °C and 75 °C, respectively and were found to be quite promising. Response of the developed sensor towards ethanol, acetone, 2-propanol, 2-butanone were also detected separately to realize their individual contribution to the resultant sensor response. Considering the TiO2 nanotube as a sensing material and following the vertical electron transport technique by using MIM sensor device, a highly stable, repeatable and low operating temperature (even at room temperature) sensor device was developed for the long term monitoring of the degradation of potato in the storage.