Internal supply of coenzyme to an amperometric glucose biosensor based on a chemically modified electrode

✍ Scribed by Mikael Skoog; Gillis Johansson

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 523 KB
• Volume: 6
• Category: Article
• ISSN: 0956-5663
• DOI: 10.1016/0956-5663(91)87005-v

✦ Synopsis

A biosensor for glucose using glucose dehydrogenase immobilized on a chemically modified graphite electrode was supplied with coenzyme, nicotinamide adenine dinucleotide (NAD+), through pores in the material. A graphite rod was hollowed out, leaving 0.3 mm at the end contacting the solution, filled with 10 mM NAD+ and pressurized. The response factor was 40% of that obtained when 2 mM NAD+ was mixed with the sample solution in a flow system. The coenzyme consumption was 11 microliters h-1 representing a 500-fold saving compared to supply through the bulk solution. The biosensor had a linear calibration curve from the detection limit, 1 microM, to 2 mM glucose and a repeatability of 0.3%. The graphite electrode was modified by adsorption of a bis-(benzophenoxazinyl)-terephthaloyl derivative in order to be able to oxidize NADH at 0 mV versus Ag/AgCl, 0.1 M KCl.