Novel functionalized multiwalled carbon nanotube-glassy carbon electrode for simultaneous determination of ascorbic acid and uric acid

Abstract

In this study the electrochemical behavior of ascorbic acid (AA) and uric acid (UA) at the surface of glassy carbon electrodes (GCEs) modified by multi-walled carbon nanotubes (MWCNTs) functionalized with Fe3+ complex was investigated. The voltammetric studies using the modified electrode showed two well-resolved anodic peaks for AA and UA with a potential difference of ∼0.4 V, revealing the possibility of the simultaneous electrochemical detection of these compounds. First, the electrochemical behavior of ferric/ferrous at Fe3+complex/MWNTs/nafion (FeCMN) modified electrode was studied. The results showed an adsorption-controlled reaction at the modified electrode. Then, the behavior of ascorbic acid and uric acid at the modified electrode was investigated. The optimum analytical conditions were sought. Linear calibration plots were obtained over the range of 4.0 to 600 μmol l−1 and 0.3 to 490 μmol l−1 with detection limits (3σ) of 2.57 μmol l−1 and 0.137 μmol l−1 for AA and UA, respectively.\nThe electrode with the best conditions was applied for selective determination of AA and UA in biological matrices.