Background & Objectives: Maintain of fixed amount of glucose in blood has always been valuable. Especially in diabetic patients it is important to determine accurate amount of it. In this study we are trying to find a method to determination of the amount of serum glucose.

Methods: First a biosensor was prepared using carbon paste electrode modified with Copper Oxide nanoparticles for determination of serum glucose. The synthesized Copper Oxide nanoparticles were studied by using a variety of chemical spectrum UV-Vis, XRD, SEM and TEM. XRD confirmed that our synthesized are Copper Oxide nanoparticles. By measuring of the oxidation currents in the several levels of glucose, the accuracy and efficiency of biosensor was studied.

Results: Based on a increase of the electrocatalytic response of the oxidized form of GOD to dissolved oxygen, the proposed biosensor exhibits a linear response to glucose concentrations ranging from 0 to 15 mM with a detection limit (defined as the concentration that could be detected at the signal-to-noise ratio of 3) of 9 �M at an applied potential of 0.44 V which has better biosensing properties than those from other biosensors. This biosensor retained 89% of its initial response after 30 days storage at pH=7.

Conclusion: Carbon paste electrode and Copper Oxide nanoparticles offer excellent catalytic activity toward hydrogen peroxide generation in enzymatic reaction between glucose oxidase and glucose, which would enable sensitive determination of glucose. This biosensor exhibited good stability, reproducibility and low interferences. It has been used to diagnose diabetes very fast and sensitively and to determine the glucose concentrations in serum samples with satisfactory results.