Electroanalytical Sensor Based on Unmodified Screen-Printed Carbon Electrode for the Determination of Levo-Thyroxine

The electrochemical behaviour of thyroxine (T4) is analysed using the disposable screen-printed carbon electrode (SPCE) in the neutral phosphate buffer solution with cyclic voltammetric technique. The Differential Pulse Voltammetry and Chronoamperometry were employed for sensing of T4. The lowest detection limit of 3nM was obtained from the differential pulse voltammetric method without preconditioning. The Density Functional Theoretical study of T4 was performed to elucidate the mechanism of oxidation. The analysis of the commercial pharmaceutical samples indicates the validity of the proposed method.