Voltammetric Determination of Curcumin in Spices using Platinum Electrode Electrochemically Modified with Poly(Vanillin-co-Caffeic Acid)

In this study a simple, highly sensitive, and selective electrochemical method was developed for determination of the low concentration curcumin (CUR) using a poly(vanillin-co-caffeic acid) p(Van-CA) modified platinum electrode. Electrode modification was carried out electrochemically with cyclic voltammetry (CV) method. For this purpose; a solution of 6 mM vanillin (Van) and 6 mM caffeic acid (CA) in phosphate buffer solution (PB) adjusted to pH 7.4 was used. Then, electrochemical behaviour of CUR on the platinum electrode modified with p(Van-CA) was investigated by using CV and differential pulse voltammetry (DPV) methods. Tween 20 as surfactant was used to increase the solubility and stability of CUR in this study. CUR responses of the modified electrode showed that it was selective, sensitive and stable. A linear calibration graph was acquired in the high concentration range of 0.1 to 1.0 mM CUR. Correlation coefficient (R-2) was calculated as 0.9951 from this linear calibration curve. The correlation coefficient for the low concentration range 0.01 to 0.07 mM was also calculated from 0.9950. LOD (limit of detection) and LOQ (limit of quantitation) of the developed method were determined as 0.005 mM and 0.015 mM, respectively. However, the detection of CUR in spices samples was made with this method. The recovery efficiency of the p(Van-CA) modified Pt electrode (p(Van-CA)/PtE) was calculated range of 96% and 102% for three different spices samples. Finally; developed method has been shown that it has fast, low cost, simple, reproducible, high accuracy and precision (99.6%) for sensitive and selective determination of CUR by using p(Van-CA)/PtE as effective novel electrode.