Electrochemical sensor based on SmHCF/multiwalled carbon nanotube modified glassy carbon electrode for dopamine

SmHCF/(MWCNT) nano structures modified glassy carbon (GC) electrode wasused as electrochemical sensor for the electro oxidation of dopamine. Ourstrategy was the combination of high electrocatalytic property of SmHCF toelectroactive biomolecule and high conductivity, surface area, and adhesiveproperties of carbon nanotubes. The presence of SmHCFnanoparticles andMWCNT was approved by Scanning electron microscopy (SEM) and cyclicvoltammetry (CV). The electrocatalytic performance of GC, SmHCF-GC, MWCNTGCand SmHCF-MWCNT-GC electrodes toward dopamine was compared andthe results cleared the enhanced electrocatalytic activity of SmHCF-MWCNT-GC(lowering the potential of the oxidation process and increased oxidation currentpeak.) relative to others. This unique combination leads to the improvement ofthe sensitivity of dopamine determination. The differential pulse voltammetrywas used for quantitative determination of dopamine. The linear dynamic rangerelationship between oxidation peak currents and dopamine concentration was2× 10-7 - 5× 10-6 (slope = 24.187 μAμM-1) with the detection limit of6× 10-8 forDA.The sensitivity of the electrode was 24.187 μAμM-1 that it is very high relativeto reported works. The relative standard deviation (RSD) of the reproducibility(5 modified electrodes), repeatability (successive 10 times), and stability (50days) of the modified electrode were 3%, 3% and 2.5% respectively. The accuracyand selectivity of the modified electrode were indicated in the real sample ashuman serum samples and in the presence of possible interfering agents. Goodselectivity and recovery were observed for the modified electrodes.