QCM SENSOR BASED ON TIN OXIDE NANOPARTICLES

Nanostructured SnO2 is widely used material in gas sensors. The aim of this study is to investigate layer deposition technique and gas sensing properties of the structure deposited on QCM resonator. Multilayer structure containing SnO2 nanolayers was prepared by Layer-by-Layer (LbL) technique. Colloidal SnO2 nanoparticles ( < 100 nm) and poly(diallyldimethylammonium chloride) (PDDA) were alternate deposited onto precursor. Well-defined precursor was assembled with (PDDA) and poly(sodium-4-styrensulfonate) (PSS). Annealing experiments were also performed by baking QCM crystal with self-assembled nanoparticles. The resonant frequency shift of the QCM resonator was evaluated during the LbL process. Effect of ionic strength of the solutions on the multilayer growth was investigated. The structure was studied by scanning electron microscopy (SEM).