Preparation and Characterization of Simple Amperometric Biosensor for Glucose with Alkali Nickel Hexacyanoferrate(II) Electrocrystallized on Nickel Electrode and Glucose Oxidase Immobilized in Bovine Serum Albumin Cross-linked with Glutaraldehyde
Stjepan Milardović1, Miroslav Mikšaj2, Ivan Kruhak2, Željka Filipović-Kovačević2 and Božidar S. Grabarić1
1Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, Croatia,
2Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, Croatia
Article history:
Received July 24, 1996
Accepted September 17, 1996
Key words:
biosensor for glucose, alkali nickel hexacyanofen-ate, nickel electrode, glucose oxidase
Summary:
Preparation and characterization of a simple amperometric enzyme-based glucose sensor is reported. The enzyme glucose oxidase is immobilized in bovine serum albumin by cross-linking with glutaraldehyde on the layer of alkali nickel hexacyanoferrate(II) electrocrystallized on the surface of nickel electrode. The selective biocatalytic effect of the enzyme glucose oxidase on the oxidation of glucose and catalytic effect of nickel electrode modified with alkali nickel hexacyanoferrate(II) on the reduction of hydrogen peroxide, produced by the ezymalic reaction, enables the amperometric glucose biosensor to operate using working potentials between -300 and -100 mV vs. SCE, where the oxidation of most important interferences present in human blood (ascorbic or uric acid) is not possible. Other characteristics of the reported biosensor are: practically independent current response of pH in the range between 6.7 and 7.7, response time for 0.3 mM glucose addition in sodium phosphate buffer solution (0.01 M phosphate ion, pH = 7.4) and 0.1 M of sodium perchlorale shorter than 20 s, relatively long time stability (during three months of operation the sensitivity decreased only 30% of the initial sensitivity) and linear range of glucose concentration up to 1.2 mM.
