Neurotransmitter Dopamine Enhanced Sensing Detection Using Fibre-Like Carbon Nanotubes by Chemical Vapor Deposition Technique

Carbon nanotubes (CNTs) are still receiving much attention in bio-sensing applications due to their remarkable properties. In this present research work, fibre-like carbon nanotubes (f-CNTs) were successfully fabricated over copper–molybdenum (Cu–Mo) substituted alumina nanoparticles at atmospheric pressure by chemical vapor deposition (CVD) technique and effectively employed as a neurotransmitter dopamine (DA) sensor. The obtained product was purified and structurally characterized by various techniques such as, field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, high resolution transmission electron microscope (HRTEM) and X-ray photoelectron spectroscopy (XPS) analysis. Structural characterization, which reveals the material contains fibre-like multi walled carbon nanotubes with graphene layers having diameter in the range of 10–20 nm and 200–300 nm inner and outer, respectively and has certain crystallinity. The weight percentages of Cu, Mo in Alumina catalyst, reaction temperature, acetylene flow rate and reaction time have been optimised to yield maximum of carbon product. Electrochemical properties of the material towards DA sensing were studied by cyclic voltammetry (CV), and diffuse pulse voltammetry (DPV) techniques. The sensor exhibits linear relationship among the peak current and DA concentration from 8 to 45 μM with detection limit of 5.3 μM (S/N = 3). The presence of structural analogues of DA has no deleterious effect on the DA anodic peak current.