Preparation, characterization of metal nanoparticle modified metal oxide electrodes by electrochemical and its biosensor applications

Nanoparticles and nanomaterials have received great interest because they are functional materials with application areas such as energy, catalysis, electrochemistry, electronics, and sensors. The oxygen reduction reaction (ORR) is a key process in controlling the performance of various clean renewable energy conversion systems such as in fuel cells and metal-air batteries. The combination of nanoparticles of precious metals and metal oxides is showed as an effective electrocatalyst for ORR. In this study, manganese and vanadium oxide (MnOx-VOx) films were synthesized pulsed deposition on multi-walled carbon nanotubes (MWCNT), and then decorated with metal nanoparticles to fabricate the MnOx-VOx film for glucose biosensor (MNPs/MnOx-VOx/CNT/GCE). Glucose oxidase (GOx) enzyme was immobilized on the MNPs/MnOx-VOx/CNT/GCE nanocomposite. The electrochemical performance of the modified biosensor was investigated using cyclic voltammetry and amperometry. Modified electrodes were characterized with scanning electron microscopy (SEM), High-resolution transmission electron microscopy (HRTEM), X-Ray photoelectron spectroscopy (XPS), X-Ray Diffraction (XRD) techniques. GOx and gold nanoparticle modified MnOx-VOx nanocomposite electrode has been used for amperometric detection of glucose. The obtained results were compared with other modified electrodes. A new electrochemical biosensor platform was constructed for the glucose detection. Dissolved oxygen in glucose biosensor studies is generally consumed during enzymatic reactions. For biosensor study, the optimum pH was selected to be 5.17. The optimum Au3+ concentration was chosen as 1.0 mM. For cycle number of metal ions, fifteen cycles was chosen as optimum in this study. The amount of glucose oxidase enzyme was selected to be 1 mg. Under optimal conditions, the calibration curves for glucose biosensor were obtained over the range of 0,1 mM – 1,0 mM. Interference studies for glucose sensor (Fructose, Galactose, Mannose, Ascorbic acid, etc.) were examined. In addition, the prepared new sensor platform was tested for repeatability between inter-day and intra-day. A new biosensor platform was tested with glucose serum sample. Also, the method successfully applied in the analysis of samples of soda and apple juice.