title: Humidity-independent solid-state amperometric sensor for carbon monoxide based on an electrolyte prepared by sol-gel chemistry.
abstract: An amperometric sensor consisting of a film of silica gel over an interdigitated microsensor electrode provided a humidity-independent response to CO over the range of 9%-76% humidity. The residual solvent contents were in the 20%-50% range, depending on the age of the gels and the humidity. Variations in this range did not change the sensitivity. Gaseous CO was quantified in the absence of a contacting liquid phase using either linear scan voltammetry (LSV) or flow injection amperometry (FIamp) at constant applied potential. With LSV after a 2-min exposure to the sample, sensors with gels aged for 28-40 days yielded sensitivities of 0.38, 0.41, and 0.38 nA/ppmv for measurements at 9%, 33%, and 76% humidity, respectively; the corresponding correlation coefficients were 0.992, 0.995, and 0.999. The detection limit with FIamp was 5 ppmv.
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Tess
authors.forename: J A
authors.initials: JA
authors.lastname: Cox
mesh_terms: D002248:Carbon Monoxide / Q000032:analysis*; D004563:Electrochemistry; D004573:Electrolytes; D006813:Humidity
chemical_list: D004573:Electrolytes; D002248:Carbon Monoxide