Simultaneous Voltammetric Determination of Uric Acid and Tryptophan by Modified Graphite Paste Electrode with Ferrocyanide Ions-doped Nano Resin Lewatit FO36 as a New Redox Probe

A novel, selective and sensitive modified graphite paste electrode (GPE) containing ferrocyanide anionic complexs (FCN) doped-Nano resin Lewatit FO36 (NRL) was designed for simultaneous determination of Uric acid (UA) and Tryptophan (Trp). The above modified electrode was investigated by various techniques such as transmission electron microscopy, Fourier transform infrared spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The electrochemical behaviour of the UA and Trp was investigated at FCNNRL/GPE by CV, differential pulse voltammetry and Chronoamperometry techniques in pH 3. Under the optimum conditions, the calibration curves were linear in the ranges of 0.4-175.2 µM and 0.5-173 µM with detection limits 10 and 30 nM, for UA and Trp, respectively. The above sensor can be successfully was used for the determination of UA and Trp with high sensitivity and accuracy in real samples.