Design and development of a new hybrid spectroelectrochemical sensor. 1998 annual progress report

'A new concept for a chemical sensor that demonstrates three modes of selectivity (electrochemistry, spectroscopy, and selective partitioning) is being developed. The spectroelectrochemical sensor consists of an optically transparent electrode (OTE) coated with a selective film. Sensing is based on the change in optical signal of light passing through the OTE that accompanies an electrochemical reaction of the analyte at the electrode surface. The purpose of this new sensor is to significantly broaden the applicability of sensors to real samples by improving selectivity. The concept is to be demonstrated with a sensor for ferrocyanide in waste from tanks at the Hanford site. This report summarizes work after 1 1/2 years of a 3-year project. The novel sensor concept has been clearly demonstrated to work. The sensor prototype consisted of an OTE made of indium tin oxide coated on glass that was coated with a sol-gel derived charge-selective thin film. Attenuated total (internal) reflection (ATR) was the optical detection mode.