Glucose Microbiosensor Based on MnO2 and Glucose Oxidase Modified Carbon Fiber Microelectrode

✍ Scribed by Samo B. Hocevar; Bozidar Ogorevc; Klemens Schachl; Kurt Kalcher

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 161 KB
• Volume: 16
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/elan.200303019

✦ Synopsis

Abstract

A glucose microbiosensor has been developed using electrochemical codeposition of glucose oxidase (GOx) along with MnO~2~ as mediator, onto a single carbon fiber microelectrode. A two‐step deposition of only MnO~2~ initially and then of MnO~2~ in the presence of GOx has been introduced to ensure appropriate activity of the mediator. Several parameters such as deposition potential and time, concentration levels etc. have been characterized and optimized. A thin Nafion film was applied as an immobilization/encapsulation and interference‐free protective layer. The proposed microbiosensor was employed as an amperometric glucose detector at pH 7.5 at an operating potential of +0.58 V (vs. Ag/AgCl). The microbiosensor is characterized by a well‐reproducible amperometric response, linear signal‐to‐glucose concentration range from 1.5 mmol L^−1^ to 15 mmol L^−1^, and a limit of detection (S/N=3) of 0.8 mmol L^−1^. The microbiosensor exhibits good stability over more than ten hours of continuous measurement.