Share Email Print
cover

Proceedings Paper

Spectroelectrochemical sensors: new polymer films for improved sensitivity
Author(s): Laura K. Morris; Carl J. Seliskar; Samuel A. Bryan; William R. Heineman
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

The selectivity of an optical sensor can be improved by combining optical detection with electrochemical oxidation or reduction of the target analyte to change its spectral properties. The changing signal can distinguish the analyte from interferences with similar spectral properties that would otherwise interfere. The analyte is detected by measuring the intensity of the electrochemically modulated signal. In one form this spectroelectrochemical sensor consists of an optically transparent electrode (OTE) coated with a film that preconcentrates the target analyte. The OTE functions as an optical waveguide for attenuated total reflectance (ATR) spectroscopy, which detects the analyte by absorption. Sensitivity relies in part on a large change in molar absorptivity between the two oxidation states used for electrochemical modulation of the optical signal. A critical part of the sensor is the ion selective film. It should preconcentrate the analyte and exclude some interferences. At the same time the film must not interfere with the electrochemistry or the optical detection. Therefore, since the debut of the sensor’s concept one major focus of our group has been developing appropriate films for different analytes. Here we report the development of a series of quaternized poly(vinylpyridine)-co-styrene (QPVP-co-S) anion exchange films for use in spectroelectrochemical sensors to enable sensitive detection of target anionic analytes in complex samples. The films were either 10% or 20% styrene and were prepared with varying degrees of quaternized pyridine groups, up to 70%. Films were characterized with respect to thickness with spectroscopic ellipsometry, degree of quaternization with FTIR, and electrochemically and spectroelectrochemically using the anions ferrocyanide and pertechnetate.

Paper Details

Date Published: 31 October 2014
PDF: 15 pages
Proc. SPIE 9253, Optics and Photonics for Counterterrorism, Crime Fighting, and Defence X; and Optical Materials and Biomaterials in Security and Defence Systems Technology XI, 925311 (31 October 2014); doi: 10.1117/12.2066892
Show Author Affiliations
Laura K. Morris, Univ. of Cincinnati (United States)
Cincinnati State Technical and Community College (United States)
Carl J. Seliskar, Univ. of Cincinnati (United States)
Samuel A. Bryan, Pacific Northwest National Lab. (United States)
William R. Heineman, Univ. of Cincinnati (United States)


Published in SPIE Proceedings Vol. 9253:
Optics and Photonics for Counterterrorism, Crime Fighting, and Defence X; and Optical Materials and Biomaterials in Security and Defence Systems Technology XI
Roberto Zamboni; Douglas Burgess; Gari Owen; François Kajzar; Attila A. Szep; Harbinder Rana, Editor(s)

© SPIE. Terms of Use
Back to Top