Preparation of a carbon nanotube-copper nanoparticle hybrid by chemical reduction for use in the electrochemical sensing of carbohydrates

Carbon nanotube (CNT)-copper nanoparticle (CuNP) hybrid was prepared by the chemical reduction of a mixture containing cupric sulfate and CNTs. The structure of the material was investigated by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The results indicated that CuNPs with an average diameter of about 15 nm were deposited on CNTs to form a well interconnected hybrid network. The material was mixed with paraffin oil and packed into the ends of fused capillaries to fabricate microdisc electrodes for sensing carbohydrates. Its analytical performance was demonstrated by sensing four carbohydrates in combination with capillary electrophoresis. The relation between peak current and analyte concentration was linear over about 3 orders of magnitude with detection limits ranging from 0.18 to 0.62 μM for all analytes.