SAW devices-sensitivity enhancement in going from 80 MHz to 1 GHz

SAW-devices with the highest resonance frequency (1 GHz) ever reported in chemical sensor applications have been tested. The sensor response increases in a parabolic manner with the resonance frequency, as is shown, in going from 80 MHz to 1 GHz, whereas the noise level only increases approximately linearly. If a linked cyclodextrin in a height of 60 nm is used as a sensitive coating, a sensor response of 61 kHz/1000 ppm of toluene is obtained. This makes the detection of aromatic hydrocarbons, such as toluene or xylene, down to 1 ppm easily possible. (C) 1998 Elsevier Science S.A. All rights reserved.