Arrayed CNT-Ni nanocomposites grown directly on Si substrate for amperometric detection of ethanol

A novel amperometric biosensor utilizing carbon nanotube (CNT)-Ni nanoparticle hybrid arrays for ethanol detection has been developed. The sensor was fabricated by e-beam deposition of thin Ni film on arrayed multi-walled carbon nanotubes grown directly on Si substrate. As the Ni film thickness is ≤ 200nm, high-resolution SEM and TEM images showed well-dispersed and strongly adhered crystalline Ni nanoparticles uniformly populated on the sidewalls of CNTs, and the sensitivity of the resultant CNT-Ni sensor generally increased with increasing nickel thickness. The best sensor showed a wide response range of 50-600 μM, a response time of <10s, and a sensitivity of 14.81 μA μM(-1)cm(-2) which is ∼380% higher in comparison with the nanostructured Ni/Pt/Ti electrodes.