Development and Characterization of Au−YSZ Surface Plasmon Resonance Based Sensing Materials:  High Temperature Detection of CO

• Published in: The journal of physical chemistry. B 2006-07, Vol.110 (27), p.13508-13511
• Main Authors: Sirinakis, George, Siddique, Rezina, Manning, Ian, Rogers, Phillip H, Carpenter, Michael A
• Format: Article
• Language: English
• ISSN: 1520-6106; 1520-5207
• DOI: 10.1021/jp062760n

Au−YSZ nanocomposite films exhibited a surface plasmon resonance absorption band around 600 nm that underwent a reversible blue shift and narrowed upon exposure to CO in air at 500 °C. A linear dependence of the sensing signal was observed for CO concentrations ranging between 0.1 and 1 vol % in an air carrier gas. This behavior of the SPR band, upon exposure to CO, was not observed when using nitrogen as the carrier gas, indicating an oxygen-dependent reaction mechanism. Additionally, the SPR band showed no measurable signal change upon exposure to CO at temperatures below ∼400 °C. The oxygen and temperature-dependent characteristics, coupled with the oxygen ion formation and conduction properties of the YSZ matrix, are indicative of charge-transfer reactions occurring at the three-phase boundary region between oxygen, Au, and YSZ, which result in charge transfer into the Au nanoparticles. These reactions are associated with the oxidation of CO and a corresponding reduction of the YSZ matrix. The chemical-reaction-induced charge injection into the Au nanoparticles results in the observed blue shift and narrowing of the SPR band.