ali akbari

A carbon paste electrode modified with 5-amino-3′,4′-dimethoxy-biphenyl-2-ol and carbon nanotubes was used for the sensitive voltammetric determination of norepinephrine (NE). The electrochemical response characteristics of the modified electrode toward NE, acetaminophen (AC), and folic acid (FA) were investigated by cyclic and square wave voltammetry (SWV). The results show an efficient catalytic activity of the electrode for the electrooxidation of NE, which leads to lowering its overpotential more than 160 mV. The modified electrode exhibits an efficient electron-mediating behavior together with well-separated oxidation peaks for NE, AC, and FA. Under the optimum pH of 7.0 in 0.1 M phosphate buffer solution, the SWV anodic peak current showed a linear relation vs. NE concentration in the range of 15.0 to 1,000.0 μM with a detection limit of 8.0 μM.