title: STW resonator with organo-functionalized metallic nanoparticle film for vapor sensing.
abstract: A 1 GHz surface transverse wave resonator on 36 degrees Y-cut quartz plate coated with organothiol-functionalized gold nanoparticle film has been studied as a chemical gas sensor. Considerable sensitivity of the resonant frequency to vapors of ethanol, methanol, chloroform, and acetic acid has been found. Owing to the high short-term stability of the oscillator built, the detection limit is in the low ppm range. The results qualitatively confirm previous results on the same film type obtained by conductivity measurements. In the present case, the conductivity effect resulting from variable separation of nanoparticles is accompanied with surface-attached mass of the absorbed gas. The film matrix exhibits considerable capacity to absorb large amounts of molecules at high gas concentrations.
authors.affiliation: Sofia University, Faculty of Physics, Department of Solid State Physics and Microelectronics, 1164 Sofia, Bulgaria.
authors.forename: Vesseline L
authors.initials: VL
authors.lastname: Strashilov
authors.forename: Gergana E
authors.initials: GE
authors.lastname: Alexieva
authors.forename: Velitchko N
authors.initials: VN
authors.lastname: Velichkov
authors.forename: Ivan D
authors.initials: ID
authors.lastname: Avramov
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Evans
mesh_terms: D019342:Acetic Acid / Q000032:analysis; D002725:Chloroform / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods; D004867:Equipment Design; D000431:Ethanol / Q000032:analysis; D005740:Gases / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D000432:Methanol / Q000032:analysis; D036103:Nanotechnology / Q000379:methods; D012680:Sensitivity and Specificity; D013499:Surface Properties; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D005740:Gases; D055549:Volatile Organic Compounds; D000431:Ethanol; D006046:Gold; D002725:Chloroform; D019342:Acetic Acid; D000432:Methanol