WO3 nanocrystals: Synthesis and application in highly sensitive detection of acetone

WO3 nanocrystals have been prepared by a sol-gel route and characterized by X-ray diffractometry, scanning electron microscopy, and transmission electron microscopy. The experimental results show that WO3 nanocrystals have a high crystallographic quality and a good dispersivity. The particles' sizes are in the range of 25-100 nm. The fabricated WO3 nanocrystal-based sensors have an excellent sensitivity and selectivity to acetone, and display a rapid response and recovery characteristics. The developed sensors exhibit a detection limit down to 0.05 ppm at 300 degrees C, rendering a promising application in noninvasive diagnosis of diabetes. The response mechanism of the WO3 nanocrystal sensor to low concentration of acetone has been discussed based on the depletion layer model. (C) 2011 Elsevier B.V. All rights reserved.