Glucose oxidase characteristics

Application of transition metal hexacyanoferrates for development of biosensors was first announced by our group in 1994 [118]. The goal was to substitute platinum as the most commonly used hydrogen peroxide transducer for Prussian blue-modified electrode. The enzyme glucose oxidase was immobilized on the top of the transducer in the polymer (Nation) membrane. The resulting biosensor showed advantageous characteristics of both sensitivity and selectivity in the presence of commonly tested reductants, such as ascorbate and paracetamol. 

Liu, Y, Liu, L., and Dong, S., Electrochemical characteristics of glucose oxidase adsorbed at carbon nanotubes modified electrode with ionic liquid as binder. Electroanalysis, 19,55-59, 2007. 

Analytes are also used to specify the application. Glucose enzyme sensor is an enzyme biosensor measuring the glucose. Characteristics and commercial varieties of enzyme electrodes, especially using glucose oxidase, have been extensively reviewed by Kuan and Guilbault (17). 

One candidate polymer system is the poly(ortho esters), which are pH-sensitive and undergo enhanced hydrolysis rates with decreasing external pH values (6). Furthermore, this system has demonstrated surface erosion characteristics and can be prepared in both linear and crosslinked forms (7., 8). The crosslinked form is particularly interesting because sensitive macromolecules can be incorporated into the polymer under very mild conditions and without denaturation. These mild conditions are important because both insulin and glucose oxidase are proteins. 

We have discussed in some detail ET reactions occurring in zeolites, mesoporous materials and sol-gels. The unifying theme across these three different types of materials is their porosity. ET reactions within the pores with molecules as small as propylene to complex enzymes such as glucose oxidase have been discussed. However, what is also apparent from the discussions are that each host matrix imposes its own unique characteristics on the reactions within its pores. We conclude by highlighting the uniqueness of each matrix. 

K. Kawakami, K. Adachi, N. Minemura, and K. Kusunoki, K., Characteristics of a honeycomb monolith three-phase bioreactor Oxidation of glucose by immobilized glucose oxidase, Kagaku Kogaku Ronbunshu 13(3)3 S (1987). 

While this paper deals with the chemistry and reaction characteristics of glucose isomerase, it should be noted that glucose oxidase, glucoamylase, aldose-1-epimerase, a-glucosidase, alcohol dehydrogenase, pullulanase, and fungal a-amylase have been successfully immobilized onto this support. 

The reaction scheme used in the first commercial electrochemical test strip from MediSense (now Abbott Diabetes Care) is shown later. Electron transfer rates between the reduced form of glucose oxidase and ferricinium ion derivatives are very rapid compared with the unwanted side reaction with oxygen (Cass et al. 1984 Forrow et al. 2002). The Abbott Diabetes Care Precision QID strip includes the l,l -dimethyl-3-(2-amino-l-hydroxyethyl) ferrocene mediator, which has the desirable characteristics of high solubility in water, fast electron-shuttling (bimolecular rate constant of 4.3 X 10 M s ), stability, and pH independence of the redox potential (Heller and Feldman 2008). Electrochemical oxidation of the ferrocene derivative is performed at 0.6 V. Oxidation of interferences, such as ascorbic acid and acetaminophen present in blood, are corrected for by measuring the current at a second electrode on the strip that does not contain glucose oxidase. 

Burow, M. Minoura, N. Molecular imprinting synthesis of polymer particles with antibody like binding characteristics for glucose oxidase. Biochem. Biophys. Res. Commun. 

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