Poly(tannic acid)- Electrochemically Reduced Graphene Oxide Nanocomposite Based Voltammetric Sensor for the Simultaneous Determination of L-dopa and Tyramine

A highly efficient voltammetric sensor for L-dopa and tyramine (TYM) has been developed based on a nanocomposite of poly(tannic acid) (p(TA)) and electrochemically reduced graphene oxide (rGO). The nanocomposite-modified electrode- p(TA)-rGO/GCE has been prepared using an electropolymerization procedure and is characterized by several analytical techniques. At the modified electrode, well-resolved peaks with enhanced peak current for L-dopa and TYM were obtained at lower overpotentials. Under optimized analytical conditions, the sensor has been used for the simultaneous determination of L-dopa in two dynamic ranges from 7.00 x 10-6 M-2.00 x 10-6 M and 1.00 x 10-6 M-1.00 x 10-7 M and TYM in the ranges from 8.00 x 10-6 M-2.00 x 10-6 M and 1.00 x 10-6 M-6.00 x 10-8 M. The proposed sensor offered high sensitivity with a limit of detection of 1.26 x 10-8 M for L-dopa and 4.73 x 10-9 M for TYM. The mechanistic aspects of the electro oxidation of the analytes were examined. The validity of the sensor has been assessed by the determination of L-dopa and TYM in artificial physiological samples and satisfactory results were obtained. poly(tannic acid) and electrochemically reduced graphene oxide nanocomposite used as a sensitive voltammetric sensor for L-dopa and tyramine.Electrocatalytic determination of L-dopa and tyramine shows the synergistic effects of the components of the modifier.High sensitivity in determination with detection limits of 1.26 x 10-8 M for L-dopa and 4.73 x 10-9 M for tyramine.Applicability studies successfully conducted in synthetic physiological samples.