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

The electrochemical behaviour of thyroxine (T-4) 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 T-4. The lowest detection limit of 3 nM was obtained from the differential pulse voltammetric method without preconditioning. The Density Functional Theoretical study of T-4 was performed to elucidate the mechanism of oxidation. The analysis of the commercial pharmaceutical samples indicates the validity of the proposed method.