Decreasing the Polymerization Potential Improves the Selectivity of PPD-Coated Disc Biosensors for Glutamate

• Published in: Analytical letters Vol. 42; no. 5; pp. 739 - 745
• Main Authors: Govindarajan, Sridhar, McNeil, Calum J.
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 01.01.2009; Taylor & Francis
• Subjects: Analytical chemistry; Biological and medical sciences; Biosensor; Biosensors; Biotechnology; Chemistry; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General, instrumentation; glutamate; Methods. Procedures. Technologies; polymerization; PPD; selectivity; Various methods and equipments; polymerization; Ascorbic acid; PPD; Biosensor; Interference; Polymer; Selectivity; Chemical sensor; Glutamate; Electrochemical polymerization
• ISSN: 0003-2719; 1532-236X
• DOI: 10.1080/00032710902721972

The selectivity of glutamate microdisc biosensors coated with poly(o-phenylenediamine) (PPD) as the interference-rejecting layer against ascorbic acid was observed to be very low. Enhancement in the selectivity was noticed when the electropolymerization potential for the polymerization of the o-phenylenediamine monomer was decreased from 0.65 V to 0.40 V vs. Ag/AgCl. The selectivity coefficient increased from −34.93±3.75% (n = 5) to 53.05 ± 4.33% (n = 3). Decreasing the polymerization potential decreases the rate of formation of the polymer and improves the compactness of the polymer layer formed, thereby increasing the selectivity of the electrodes.