Determination of ascorbic acid at solid electrodes modified with L-cysteine

Gold and glassy carbon electrode surfaces were modified with L-cysteine, the electrochemical behavior of ascorbic acid (AA) was investigated on these new surfaces. To improve efficiency electrodes, optimum conditions for AA determination established. Electrochemical experiments performed at different potential ranges, concentration AA, scan rates, number polymerization cycles pH values. Using cyclic voltammetry (CV) technique, determined as scanning range 0.2 to 1.5 V vs. Ag/AgCl in 0.1 M phosphate buffer solution (pH 7.02) L-cysteine/Au electrode, -1.95 1.9 2.7) L-cysteine/GC electrode. For characterization both surfaces, a series physicochemical techniques also applied. The usability selectivity two proposed electrodes using square wave (SWV) presence possible interferents, i.e., glycine, L-glutamic uric acid.