Copper/nickel nanoparticle decorated carbon nanotubes for nonenzymatic glucose biosensor

In this study, copper/nickel (CuNi) particle decorated multiwalled carbon nanotubes (MWCNTs) have been fabricated for nonenzymatic glucose detection by the electrodeposition of CuNi particles on a glassy carbon electrode (GCE) modified with Nafion-functionalized MWCNTs (fMWCNTs). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses reveal that CuNi particles were successfully deposited on the fMWCNTs/GCE. The as-synthesized CuNi/fMWCNT composite reveals the shape characteristics of dendrite with a Cu/Ni atomic ratio of around 88.1/11.9. The nonenzymatic glucose sensor based on CuNi/fMWCNT composite shows excellent electrocatalytic activity toward glucose oxidation with a high sensitivity (1470.2 mu A cm(-2) mM(-1)), a low detection limit (2.5 nM, signal/noise (S/N) ratio = 3), and a wide linear range (0.1-5000 mu M). Moreover, the sensor has been successfully used for the assay of glucose in human serum samples with good recovery, ranging from 95.6 to 100.1 %. These results indicate that CuNi/fMWCNT composite is an ideal candidate for novel nonenzymatic glucose sensor because of its high sensitivity, good selectivity, good stability, and low cost.