Electrochemical behavior and analytical detection of insulin on pretreated nanocarbon black electrode surface

This work takes advantage of electrochemically anodic pretreated carbon paste electrode modified with acetylene black nanocarbon particles (AB/CPE), a new and high-sensitive analytical method for insulin was put forward. Modern voltammetric testing techniques were used for primarily investigating the redox electrochemical characterization of Fe(CN)63−/4− and electrochemical behavior of insulin on nanocarbon electrode surface. At the same time, a plausible mechanism was also proposed to provide insights into understanding how to facilitate the electron transfer between insulin biomolecule and electrode surface. The results have shown that the pretreated AB/CPE represented high accumulation efficiency to insulin and promoted its direct electron transfer rate owing to the presence of nanocarbon particles and anodic pretreatment. It is found that insulin exhibited a very sensitive anodic peak at 0.47 V on the pretreated AB/CPE, and its peak current was increased about six times more than that on the pretreated carbon paste electrode (CPE). A linear relationship between the anodic peak current and the concentration of insulin from 20 to 1000 nM and a limit of detection as low as 5 nM were obtained using the pretreated AB/CPE. Attracting attention, the proposed method was applied to the realistic samples successfully and showed good recovery and reproducibility.