High performance non-enzymatic glucose biosensor based on copper nanowires–carbon nanotubes hybrid for intracellular glucose study

In order to detect low concentration of glucose in cell sample conveniently, a glucose biosensor with high sensitivity and low detection limit was fabricated by modifying one-dimensional ultra-long Cu nanowires (Cu NWs) and multi-walled carbon nanotubes (MWCNTs) hybrid on the surface of glassy carbon electrode (GCE). Cu NWs with uniform diameter were synthesized by a facile approach in large scale and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD). The electrocatalytic activity of the as-prepared biosensor towards glucose oxidation was investigated by cyclic voltammetry and amperometric measurement in alkaline media. The results showed that the biosensor exhibited a rapid response time of less than 1 s and high sensitivity of 1995 μAm M−1 cm−2 with a wide linear range (up to 3 mM) and low detection limit (0.26 μM at signal/noise ratio (S/N) = 3). For practical application, the biosensor was successfully applied to detect glucose in serum and study the relationship between the glucose concentrations in cultivated cells and the glucose concentrations in culture mediums, in which the cells were cultivated. All the experiment results showed that the Cu NWs–MWCNTs hybrid had great potential applications in the development of biosensors for enzyme-free detection of low concentration glucose.