Abstract: Anbutylamine plasma coated thicknessshearmode(TSM) acoustic wave sensor was prepared on the surface of quartz crystal using a plasma deposited technique. The response characteristics of the TSM sensor for a series of organic vapors were reported. It shows that the TSM can be used for sensing carboxylic acid vapor efficiently and possesses considerably long lifetime compared with the sensor coated by common chemical polymer. The sensor possessed good reproducibility, high stability and rapid response time to formic acid while coating with 96.40 g of plasmadeposited nbutylamine. Compared with acidbase titration method, the sensor can be .used for the determination of HCOOH sample with recovery rate of 96.6% to 104.2%.

Key words: n-Butylamine, Plasmadeposited film, Thickness-shear-mode acoustic wave sensor, Carboxylic acid vapor, Long lifetime for usage