Electrochemical glucose sensor based on one-step construction of gold nanoparticle–chitosan composite film

A simple and controllable electrodeposition method for the preparation of a chitosan–gold nanoparticles (GNPs) nanocomposite sensing film on a glassy carbon electrode (GCE) surface was proposed and further used for the construction of an glucose non-enzymatic sensor. This novel interface embedded in situ GNPs in chitosan hydrogel was constructed by one-step electrochemical deposition in solution containing tetrachloroauric (III) acid (HAuCl4) and chitosan. This deposited interface possessed excellent stability by the characterization of cyclic voltammetry and pulse voltammetry in phosphate buffer (pH 7.10). The application in serum analysis as a possible alternative for electrochemical detection of glucose has been investigated. Several key operational parameters affecting the electrochemical response of nanostructured sensing film were examined and optimized, such as deposition conditions, scan rate, electrolyte and its pH values. As the nanostructured sensing film provides plenty of active sites for the direct oxidation of glucose, the glucose sensor exhibited excellent performance including wide linearity, simple operation and good stability at the optimized conditions. The glucose sensor exhibited good linear behavior in the concentration range from 4.00 × 10−4 mol/L to 1.07 × 10−2 mol/L for the quantitative analysis of glucose with a limit of detection of 3.70 × 10−4 mol/L. Finally, it has been demonstrated that this sensor can be well used for the assay of glucose in rat serum samples.