Amperometric biosensors based on the immobilization of oxidases in a Prussian blue film by electrochemical codeposition

✍ Scribed by Qijin Chi; Shaojun Dong

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 687 KB
• Volume: 310
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(95)00152-p

✦ Synopsis

Prussian blue has been formed by cyclic voltammetry onto the basal pyrolytic graphite surface to prepare a chemically modified electrode which provides excellent electrocatalysis for both oxidation and reduction of hydrogen peroxide. It is found for the first time that glucose oxidase or D-amino oxidase can be incorporated into a Prussian blue film during its electrochemical growth process. Two amperometric biosensors were fabricated by electrochemical codeposition, and the resulting sensors were protected by coverage with a thin film of Nafion. The influence of various experimental conditions was examined for optimum analytical performance. The glucose sensor responds rapidly to substrates with a detection limit of 2 X 10m6 M and a linear concentration range of 0.01-3 mM. There was no interference from 2 mM ascorbic acid or uric acid. Another (o-amino acid) sensor gave a detection limit of 3 X lo-' M D-shine, injected with a linear concentration range of 7.0 X lo-'-l.4

X lo-' M. Glucose and n-amino acid sensors remain relatively stable for 20 and 15 days, respectively. There is no obvious interference from anion electroactive species due to a low operating potential and excellent pemrselectivity of Nafion.