2, 4-Dinitrophenylhydrazine @ Phosphatidylcholine Modified GC Electrode: Voltammetrically Distinguishing Dopamine, Uric Acid and Ascorbic Acid

Glassy carbon electrode surface was modified by 2, 4-dinitrophenylhydrazine encapsulated phosphatidylcholine film. The modified electrode shifted the cyclic voltammogram of dopamine (DA) to 0.195 V ± 0.005 V in positive direction compared to that of DA at the bare electrode. The cyclic voltammogram of uric acid (UA) was shifted at the modified electrode to the high value of 1.245 V in negative direction. The irreversible cyclic voltammogram of ascorbic acid (AA), observed by bare glassy carbon electrode, was not affected when modified glassy carbon electrode was used but a decrease in current value was observed. The cyclic voltammogram of DA recorded with the modified electrode remains unaltered even in presence of 10⁴ times of AA in the electrolytic medium. The response time of the electrode towards DA and UA was found to be 8 and 9 seconds, respectively. The detection limit of the electrode was observed to be ca. 0.01 mM for both DA and uric acid.