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Abstract
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Diabetes mellitus is a worldwide public health problem. This metabolic disorder results from insulin deficiency and hyperglycemia and is reflected by blood glucose concentrations higher or lower than the normal range of 4.4-6.6 mM. Hence, the diagnosis and management of diabetes mellitus thus requires a tight monitoring of blood glucose levels [1]. Several methods have been proposed for the determination of the glucose, however, the electrochemical sensors are especially promising because of their simplicity, high sensitivity and selectivity.
A promising electrochemical sensor for determination of glucose was fabricated by electrodeposition of cobalt oxide nanoparticles on graphene paste electrode (GrPE). GrPE was prepared by mixing graphene nanosheets and mineral oil in a mortar. The prepared electrode was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Then, the electrodeposition of cobalt oxide nanoparticles was done by a cyclical voltage process. The morphology of modified electrode was studied by field emission scanning electron microscopy and electrochemical behavior was studied by cyclic voltammetry and chronoamperometry. The modified electrode showed electrocatalytic activity toward the oxidation of glucose and was used as an amperometric sensor. The performance of the sensor exhibited a linear range from 40 to 4000 μM with low a limit of detection of 1.44 μM (S/N = 3) and the sensitivity of the sensor was found to be 1.21 μA μM-1 cm-2. The modified electrode was successfully used for the analysis of glucose in human blood serum samples, which demonstrating the applicability of the modified electrode.
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