Preparation of Polycurcumin-Modified Graphite Electrode via Electropolymerization and its Application for Determining Cd2+

The graphite electrode was changed by applying cyclic voltammetry to electropolymerized curcumin. Then, the polycurcumin-modified graphite electrodes (GECU) were used to determine Cd2+ concentration. The results showed that the GECU electrodes had higher electrocatalytic activity toward Cd2+ than bare graphite electrodes. Furthermore, the effect of the scan rates showed that the electrochemical process controlling the redox behavior of Cd2+ on GECU is a diffusion-controlled electrochemical process. At Cd2+ ranging from 0.22 to 11.03 ppm, the relationship between oxidation peak current (Ip) and Cd2+ concentration follows the linear regression equation of Ip = 73.024[Cd2+] + 722.02 (μA, R2 = 0.9936). It means that under experimental conditions, an increase in Cd2+ from 0.22 to 11.03 ppm can increase the Ip value. On the other hand, At Cd2+ ranging from 11.03 to 55.07 ppm, the relationship between Ip and Cd2+ concentration follows the linear equation of Ip = 24.227[Cd2+] + 1212.6 (μA, R2 = 0.9920). The LOD and LOQ were determined at low Cd2+ concentrations, namely 0.86 ppm, and 2.84 ppm, respectively. Furthermore, the suggested modification has been used successfully and with satisfactory recoveries to determine the presence of Cd2+ in laboratory liquid wastewater.