Modifications of Poly(o-phenylenediamine) Permselective Layer on Pt-Ir for Biosensor Application in Neurochemical Monitoring

• Main Authors: Robert D. O’Neill, John P. Lowry, Pier A. Serra, Kylie B. O’Brien, Sarah J. Killoran, Jennifer D. Craig, Colm P. McMahon, Gaia Rocchitta, Sarah M. Kirwan
• Format: Article
• Language: English
• Published: MDPI AG 2007-04-01
• Series: Sensors
• Subjects: Platinum-iridium electrodes; Polymer electrosynthesis; Cyclic voltammetry; Amperometry; Proteins; Cyclodextrins; Ascorbate; Hydrogen peroxide; Brain analysis.
• Online Access: http://www.mdpi.com/1424-8220/7/4/420/

Reports that globular proteins could enhance the interference blocking ability ofthe PPD (poly(o-phenylenediamine) layer used as a permselective barrier in biosensordesign, prompted this study where a variety of modifying agents were incorporated into PPDduring its electrosynthesis on Pt-Ir electrodes. Trapped molecules, including fibrous proteinsand β-cyclodextrin, altered the polymer/modifier composite selectivity by affecting thesensitivity to both H2O2 (signal molecule in many enzyme-based biosensors) and thearchetypal interference species, ascorbic acid. A comparison of electrochemical properties ofPt and a Pt-Ir alloy suggests that the benefits of the latter, more rigid, metal can be exploitedin PPD-based biosensor design without significant loss of backward compatibility withstudies involving pure Pt.