Biomimetic Sensor for Dobutamine Employing Nano-TiO2/Nafion/Carbon Nanoparticles Modified Electrode

摘要

A novel voltammetric biosensor based on nano-TiO2afion/carbon nanoparticles modified glassy carbon electrode (TiO2/N/CNP/GCE) was developed for the determination of dobutamine (DBA). Characterization of the surface morphology and property of TiO2/N/CNP layer was carried out by the scanning electron microscopy and atomic force microscopy. The electrochemical performance of the modified electrode was investigated by means of the cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy techniques. Effective experimental variables, such as the scan rate, pH of the supporting electrolyte, drop size of the casted modifier suspension and accumulation conditions of DBA on the surface of TiO2/N/CNP/GCE were optimized. Under the optimized conditions, a significant electrochemical improvement was observed toward the electro-oxidation of DBA on the surface of TiO2/N/CNP/GCE compared to the bare GCE. Under the optimized conditions, a wide linear dynamic range (6 nM-1 mu M) with a low detection limit of 2 nM for DBA was resulted. The prepared modified electrode shows high sensitivity, stability and good reproducibility in the determination of DBA concentrations. Satisfactory results were obtained for DBA analysis in the pharmaceutical and clinical preparations using TiO2/N/CNP/GCE.