Sequential Electro-Deposition of Highly Stable Cu-Fe Prussian Blue Coordination Polymers at Indium Tin Oxide Electrode: Characterization and the Enhanced Sensing Application

In this paper, copper hexacyanoferrate (CuHCF), a Prussian blue-type coordination polymer was synthesized to modify indium tin oxide (ITO) electrode using the facile derivatization of the pre-electrodeposited metallic copper in a solution containing hexacyano-ferrate (E) for the first time. The obtained ITO/CuHCF possesses a typical surface-confined behavior with a pair of stable and symmetrical redox signal at around 0.65 V vs. SCE at scan rate of 10 mV s(-1). Moreover, the ITO/CuHCF exhibits an enhanced analytical performance for amperometric detection of captopril with an enlarged linear range from 6.0 x 10(-7) to 5.3 x 10(-4) mol L-1, a low detection limit (0.43 mu mol L-1) and a high sensitivity (68.86 mu A mmol L-1 cm(-2)). This proposed sensor has been successfully applied to determine captopril in commercial tablet and urine samples. (C) 2015 The Electrochemical Society. All rights reserved.