Poly(Xylene Cyanol FF) Chemical Sensor for the Boost Up of Electro-Catalytic Oxidation of L-Dopa in the Presence of Ascorbic Acid and Uric Acid: A Voltammetric Study

摘要

The electrochemical behaviour of L-dopa (3,4-dihydroxy L-phenylalanine) was studied in a sensitive and selective manner through the surface modification with a poly-Xylene cyanol FF (poly-XCyFF) film on the carbon paste electrode (CPE) by employing voltammetric techniques. The modified electrode exhibited good promotion of electrocatalytic action towards the electrochemical investigation of L-dopa in 0.1 M phosphate buffer solution (PBS) of pH 5.0. Poly-XCyFFMCPE was found to exhibit good resolution and response towards the simultaneous determination of L-dopa in the presence of high concentration of ascorbic acid (AA) and uric acid (UA) in PBS. The effect of pH, scan rate, preconcentration time and concentration of L-dopa was studied at the fabricated polymer film electrode. The voltammetric peak currents showed a linear relation of L-dopa concentration in the range from 20 × 10~(-6) M to 9 × 10~(-3) M, with a detection limit of 1.8 μM, quantification limit of 6.0 μM and correlation coefficient of 0.9925 respectively. The poly-XCyFFMCPE was successfully applied towards the determination of L-dopa in pharmaceutical formulation. The electron transfer kinetics of redox probe at poly-XCyFFMCPE was studied by employing electrochemical impedance measurement. In conclusion this study illustrated that the proposed electrode modified with XCyFF is of high sensitive, more accurate, good precision and suitable for selective determination of L-dopa in comparison with bare CPE.