Polyelectrolyte and molecular host ion self-assembly to multilayer thin films: An approach to thin film chemical sensors

Multilayer molecular films of polyelectrolyte/calixarene and polyelectrolyte/cyclodextrin hosts were fabricated by alternating adsorption of charged species in aqueous solutions onto a substrate (quartz or silicon wafer). This layer-by-layer molecular deposition approach has been successfully used to integrate molecular recognition reagents into polymer films as chemically selective layers for surface acoustic wave (SAW) chemical sensing applications. The resulting sensors have high sensitivity and selectivity to the organic vapors studied. The films were characterized with SEM, infrared and W-vis spectroscopy, and monitored by SAW devices. These measurements revealed that the deposition process is highly reproducible and the resulting films are uniform and stable. (C) 1997 Elsevier Science S.A.