Self-assembly of carbon nanotubes and alumina-coated silica nanoparticles on a glassy carbon electrode for electroanalysis

A novel method for attaching multiwalled carbon nanotube-alumina-coated silica (MWCNT-ACS) composite onto the surface of glassy carbon by a self-assembly process is described. The resulting MWCNT-ACS modified glassy carbon electrode was investigated by atomic force microscopy. In cyclic voltammetric responses, both anodic and cathodic peak currents varied linearly with the square root of scan rates in 0.1 M KCl containing 5 mM Fe(CN)64- at MWCNT-ACS-coated glassy carbon electrode, which suggests a diffusion-controlled process. The MWCNT-ACS modified glassy carbon electrode exhibits the abilities to raise the current responses and to decrease the electrooxidation potential of β-nicotinamide adenine dinucleotide (NADH) and hydrogen peroxide, which is crucial in preparation of amperometric dehydrogenase- and oxidase-based biosensors.