title: Small-Area, Resistive Volatile Organic Compound (VOC) Sensors Using Metal-Polymer Hybrid Film Based on Oxidative Chemical Vapor Deposition (oCVD).
abstract: We report a novel room temperature methanol sensor comprised of gold nanoparticles covalently attached to the surface of conducting copolymer films. The copolymer films are synthesized by oxidative chemical vapor deposition (oCVD), allowing substrate-independent deposition, good polymer conductivity and stability. Two different oCVD copolymers are examined: poly(3,4-ethylenedioxythiophene-co-thiophene-3-aceticacid)[poly(EDOT-co-TAA)] and poly(3,4-ehylenedioxythiophene-co-thiophene-3-ethanol)[poly(EDOT-co-3-TE)]. Covalent attachment of gold nanoparticles to the functional groups of the oCVD films results in a hybrid system with efficient sensing response to methanol. The response of the poly(EDOT-co-TAA)/Au devices is found to be superior to that of the other copolymer, confirming the importance of the linker molecules (4-aminothiophenol) in the sensing behavior. Selectivity of the sensor to methanol over n-pentane, acetone, and toluene is demonstrated. Direct fabrication on a printed circuit board (PCB) is achieved, resulting in an improved electrical contact of the organic resistor to the metal circuitry and thus enhanced sensing properties. The simplicity and low fabrication cost of the resistive element, mild working temperature, together with its compatibility with PCB substrates pave the way for its straightforward integration into electronic devices, such as wireless sensor networks.
authors.forename: Xiaoxue
authors.initials: X
authors.lastname: Wang
authors.affiliation: ‡Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Sichao
authors.initials: S
authors.lastname: Hou
authors.forename: Hilal
authors.initials: H
authors.lastname: Goktas
authors.forename: Peter
authors.initials: P
authors.lastname: Kovacik
authors.forename: Frank
authors.initials: F
authors.lastname: Yaul
authors.forename: Arun
authors.initials: A
authors.lastname: Paidimarri
authors.forename: Nathan
authors.initials: N
authors.lastname: Ickes
authors.forename: Anantha
authors.initials: A
authors.lastname: Chandrakasan
authors.forename: Karen
authors.initials: K
authors.lastname: Gleason
keywords: conducting polymer; gold nanoparticle; oCVD; printed circuit board; sensor