Absorbance-based spectroelectrochemical sensor for [Re(dmpe)3]+ (dmpe=dimethylphosphinoethane)

Abstract

A spectroelectrochemical sensor was developed for [Re(dmpe)3]+ as a nonradioactive analog for [Tc(dmpe)3]+. The sensor consists of an optically transparent electrode (OTE) coated with a thin film of sulfonated polystyrene-blockpoly(ethylene-ran-butylene)-block-polystyrene (SSEBS). Colorless [Re(dmpe)3]+ was reversibly oxidized to [Re(dmpe)3]2+ (Λmax=530 nm). [Re(dmpe)3]+ preconcentrated by ion-exchange into the SSEBS film, resulting in a 20-fold increase in peak current compared to a bare OTE after 1 h of exposure to aqueous [Re(dmpe)3]+ solution. Detection of [Re(dmpe)3]+ at concentrations down to 2×10-6 M was accomplished by electrochemical modulation of the complex and monitoring absorbance by attenuated total reflectance (ATR). © 2009 Wiley-VCH Verlag GmbH & Co.