Polyelectrolyte-stabilized glucose biosensor based on woodceramics as electrode.

Abstract

OBJECTIVE: Different biosensors for early diagnosis of diabetes have been discussed increasingly. We demonstrate the applicability of a glucose biosensor for rapid and quantitative determination of glucose in experimental sample solutions. DESIGN AND METHODS: Polyethylenimine (PEI)-stabilized glucose oxidase (GOD) was used for the construction of stable glucose biosensor utilizing a simple manufacture procedure. The stabilized glucose oxidase was immobilized by physical adsorption into activated porous and conductive carbonaceous material-woodceramics that served as the immobilization matrix and the electrochemical transducer. The optimum parameters for the construction of the biosensor and the influences of pH and temperature on the biosensor response were explored. RESULTS: Optimum results were obtained using soaking solutions of 2300 U/ml GOD, 10 mg/ml mediator toluidine blue O (TBO), and 2.0%, w/v PEI. The sensitivity of the resulting biosensor for glucose was 1.22 microA/mM, with a linear response in the concentration range of 0.5-7 mM. The sensor-to-sensor reproducibility was good, the relative standard deviation (R.S.D.) being less than 8.0%. The storage and operational stabilities of the glucose biosensor were good. CONCLUSIONS: The glucose biosensor provides reproducible and quantitative information on glucose within minutes and is applicable for the detection of glucose in experimental samples.