Quartz sensor array using mesoporous silica hybrids for gas sensing applications

Mesoporous silica films prepared by sol gel process and argon plasma calcination have been used to form hybrids for gas sensing applications. Silica hybrids are obtained by incorporating various receptor molecules in the porous network through physiosorption and (or) chemical bonding between the silica matrix and receptor molecules. Plasma calcination, a low temperature process, is employed as the gelation tool instead of conventional thermal calcination. FESEM, FT-IR, SIMS and nitrogen adsorption analysis are used to characterize the obtained films. Quartz crystal microbalance (QCM: 5 MHz to 10 MHz) coated with silica hybrid films is tested as a sensor for selectively capturing target analytes. The frequency interference between the individual QCM in the array has been eliminated by appropriate positioning of the electrodes. It is concluded that QCM array sensitivity and selectivity could be enhanced by depositing plasma calcined mesoporous hybrids on the electrodes