Applications of nanomaterials to biosensors have recently aroused much interest. This is because these interesting materials exhibit large surface-to-volume ratio, high surface reaction activity, high catalytic efficiency, and strong adsorption ability that are helpful for the immobilization of desired biosensing molecules including glucose oxidase. Moreover, nanoparticles have a unique ability to promote fast electron transfer between electrode and the active site of the enzyme [1]. In this context, different types of nanoparticles [2,3] have been suggested as promising matrixses for enzyme immobilization to improve stability and sensitivity of a biosensor. In this paper, a facile method for synthesis of Cu2O nanoparticles on the functionalized surfaces of silica nanoparticles has been investigated.Cu2O nanoparticles where synthesized readily with size of 4-5 nm using a simple route of sol-gel method. The prepared SiO2@Cu2O core shell nanoparticles were characterized by XRD, TEM and FTIR. A Chitosan (0.50%) solution was prepared by dissolving CH in acetate buffer. SiO2@Cu2O core-shell nanoparticle was dispersed in the CH solution by sonicating at room temperature. The film of nanocomposite was fabricated by dipcoating solution of CH–SiO2@Cu2O core-shell nanoparticle onto a FTO surface and allowing it to dry at room temperature for about 12 h. Solution of GOx (1mg/ml in phosphate buffer, 50 mM, and pH 7.0) was immobilized on to CH–SiO2@Cu2O core-shell nanoparticle electrode by physisorption. This bioelectrode was allowed to dry at room temperature for about 5 h. Electrochemical studies have been carried out on an potentiostat/galvanostat (μ Autolab Type III) using a three-electrode system. The present sensor showed excellent properties for the sensitive determination of glucose with good reproducibility, remarkable stability, and rapid response. Compared with the other types of biosensors for glucose detection, the preparation of CH-SiO2@Cu2O core-shell nanoparticles composite electrode is simple and fast.

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