Facile synthesis of nanospindle-like Cu2O/straight multi-walled carbon nanotube hybrid nanostructures and their application in enzyme-free glucose sensing

A type of nanospindle-like Cu2O/straight multi-walled carbon nanotubes (SMWNTs) nanohybrids modified electrode for sensitive enzyme-free glucose detection has been fabricated, where the morphology of the nanohybrids were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). The electrochemical characteristics of this electrode material were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The as-prepared nanospindle-like Cu2O/SMWNTs nanohybrids exhibit much higher electrocatalytic activity on the oxidation of glucose than the SMWNTs or Cu2O alone as the electrode modifying material, which attributes to high catalytic active sites provided by the nanospindle-like Cu2O and high electron transfer rate provided by an efficient electrical network formed by Cu2O and SMWNTs. The proposed sensors exhibit linear behavior in the concentration range from 500 nM to 2.5 mM for glucose with a high sensitivity of 2143 μA mM−1 cm−2 and a limit of detection of 200 nM (3σ). More importantly, the nanohybrids modified electrode also show good stability, reproducibility and high resistance against poisoning by chloride ion and the commonly interfering species such as ascorbic acid, dopamine, uric acid and acetamidophenol. These good analytical performances make the nanospindle-like Cu2O/SMWNTs nanohybrids promising for the future development of enzyme-free glucose sensors.