Study Of Nonenzymatic Dopamine Electrochemical Sensor Based On Multiwall Carbon Nanotubles/Graphene Oxide Nanoribbons Nanocomposite

Dopamine (DA), a typical neurotransmitter, plays a significant role in the physiological research, clinical application and food safety. Chemical modified electrodes, a simpler and more sensitive technique, have been widly applied in electrochemical analysis. Multiwall carbon nanotubes (MWCNTs) and graphene (G), the novel allotropes of carbon, have been proposed as promising support materials for electrochemical sensor owing to the high electrical conductivity, unique electrochemical properties and splendiferous mass transport capability. Herein, we developed an unprecedented method for generating the multiwall carbon nanotubes /graphene oxide nanoribbons (MWCNTs/GORs). Assembling the intriguing properties of MWCNTs and GORs, this prepared material exhibits more active sites, higher surface area and faster electronic transfer rates. Moreover, the MWCNTs/GORs nanocomposite can directly serve as catalyst and used to modify glassy carbon electrode (GCE) with excellent electrochemical catalytic performance of DA. The morphology and structures of the obtained catalysts have been investigated by scanning electron microscopy (SEM), field-emission transmission electron microscope (FE-TEM), energy dispersive X-ray spectroscopy (EDS) and Raman spectroscopy (Raman). Electrochemical cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronocoulometry methods were used to evaluate the electrocatalytic catalytic performance of DA. The main contents in this work are listed in the following:Multiwall carbon nanotubes (MWCNTs)/graphene oxide nanoribbons (GORs) nanocomposite fabricated by a novel chemical oxidation method was used for electrochemical detection of dopamine (DA). Characterization data reveal that MWCNTs/GORs nanocomposite possesses well developed three-dimensional bamboo-like structure and large specific surface area as well as good electrical conductivity. Electrochemical analytical parameters such as diffusion coefficient, electron transfer number and electrode reaction rate constant suggest that the nanocomposite displays superior electrocatalytic activity towards the oxidation of DA and the peak currents present a good linear relationship to the concentrations ranging from 0.5 to 400.0 μM with a detection limit of 60 nM (S/N=3). The prepared electrochemical biosensor was applied to determine DA in pharmaceutical dopamine hydrochloride injection with satisfactory results.