Cross-linked redox gels containing glucose oxidase for amperometric biosensor applications

Journal Article · Thu Feb 01 00:00:00 EST 1990 · Analytical Chemistry (Washington); (USA)

DOI:https://doi.org/10.1021/ac00202a007· OSTI ID:7087297

Gregg, B A; Heller, A ^[1]

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1. Univ. of Texas, Austin (USA)

Oxidoreductases, such as glucose oxidase, can be electrically wired to electrodes by electrostatic complexing or by covalent binding of redox polymers so that the electrons flow from the enzyme, through the polymer, to the electrode. We describe two materials for amperometric biosensors based on a cross-linkable poly(vinylpyridine) complex of (Os-(bpy){sub 2}Cl){sup +/2+} that communicates electrically with flavin adenine dinucleiotide redox centers of enzymes such as glucose oxidase. The uncomplexed pyridines of the poly(vinylpyridine) are quaternized with two types of groups, one promoting hydrophilicity (2-bromoethanol or 3-bromopropionic acid), the other containing an active ester (N-hydroxysuccinimide) that forms amide bonds with both lysines on the enzyme surface and with an added polyamine cross-linking agent (tri-ethylenetetraamine, trien). In the presence of glucose oxidase and trien this polymer forms rugged, cross-linked, electroactive films on the surface of electrodes, thereby eliminating the requirement for a membrane for containing the enzyme and redox couple. The glucose response time of the resulting electrodes is less than 10 s. The glucose response under N{sub 2} shows an apparent Michaelis constant, K{sub m}{prime} = 7.3 mM, and limiting current densities, j{sub max}, between 100 and 800 {mu}A/cm{sup 2}. Currents are decreased by 30-50% in air-saturated solutions because of competition between O{sub 2} and the Os(III) complex for electrons from the reduced enzyme. Rotating ring disk experiments in air-saturated solutions containing 10 mM glucose show that about 20% of the active enzyme is electrooxidized via the Os(III) complex, while the rest is oxidized by O{sub 2}. These results suggest that only part of the active enzyme is in electrical contact with the electrode.

• OSTI ID: 7087297
• Journal Information: Analytical Chemistry (Washington); (USA), Vol. 62:3; ISSN 0003-2700
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
GLUCOSE
AMPEROMETRY
OXYGENASES
BIOCHEMICAL REACTION KINETICS
BIOTECHNOLOGY
DATA ANALYSIS
ELECTRODES
EXPERIMENTAL DATA
MEASURING INSTRUMENTS
MEASURING METHODS
ALDEHYDES
CARBOHYDRATES
DATA
ENZYMES
HEXOSES
INFORMATION
KINETICS
MONOSACCHARIDES
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDOREDUCTASES
REACTION KINETICS
SACCHARIDES
TITRATION
090900* - Biomass Fuels- Processing- (1990-)