Electrochemical sensor studies of dopamine using multiwalled carbon nanotubes by CVD technique

The synthesized Multiwall carbon nanotubes (MWCNTs) structural conformation studies were carried out using the powder X-ray diffraction. Plane 002 shows the crystallinity of graphite hexagonal carbon structure. The Fourier transform spectroscopy shows the presence of C--C double bond which reveals the presence of MWCNTs. Morphology and Elemental analysis were studied by SEM-EDX analysis. HR-TEM and SAED pattern shows that the formation of MWCNTs and the same is matched with XRD pattern. In addition to that, the thermal stability of the MWCNTs was carried out using differential scanning calorimetry and thermo-gravimetric analysis. The UV-visible spectroscopy shows the strong absorption band at 357 nm and the corresponding energy band gap was found to be 3.34ev. In the present study the synthesized MWCNTs used as bare carbon paste electrode (BCPE) and modified carbon paste electrode (MCPE) to study the electrochemical biosensor behavior of dopamine (DA) using the cyclic voltammetric technique. DA represents the oxidation peak is 0.1009 V and 0.1049 V and also the reduction peak is 0.1470 V and 0.1522 V at the BCPE and MWCNT/MCPE. Hence the oxidation and reduction peak range of DA at the modified MWCNTs were significantly higher. The electron transfer reaction of DA is shown by the effect of scan rate and the concentration of dopamine. The modified electrode's stability was investigated with the outcomes indicating it is relatively stable. The developed sensor had a high level of sensitivity, stability, and reproducibility.