Catechol sensor based on ascorbate oxidase immobilized polymer-modified graphite electrode

✍ Scribed by Toshihiko Imato; Hironori Morioka; William R. Heineman

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 450 KB
• Volume: 13
• Category: Article
• ISSN: 0925-4005
• DOI: 10.1016/0925-4005(93)85325-5

✦ Synopsis

A selectivity and sensitivity enhanced catechol sensor based on a polymer-modified graphite electrode was fabricated by immobilizing ascorbate oxidase (AO) into a poly(Nviny1 pyrrolidone) (PNVP) membrane. A0 was immobilized between two PNVP membrane layers as a sandwiched structure by cross-linking PNVP wijl~ gamma radiation.

The sensor responses to catechol and ascorbic acid were evaluated by cyclic voltammetry. The sensor showed a selective response to catechd even in the presence of ascorbic acid, which was due to blocking ascorbic acid access to the electrode surface by the enzymatic activity of A0 immobilized in tbe polymer membrane. Compared to a bare electrode without modification with the PNVP membrane, an enhanced response of the sensor to catechol was observed, which was due to preconcentration of catechol into the PNVP membrane. The enzymatic activity of A0 immobilized on the sensor surface did not change for at least four days.