Simultaneous determination of tyrosine, acetaminophen and ascorbic acid using gold nanoparticles/multiwalled carbon nanotube/glassy carbon electrode by differential pulse voltammetric method

A simple strategy for simultaneous determination of tyrosine (Tyr), acetaminophen (AC) and ascorbic acid (AA) based on gold nanoparticles/multiwalled carbon nanotube nanocomposite modified glassy carbon electrode (AuNPs/MWCNT/GCE) is reported. Scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to characterize the performance and microstructure of the sensor. The AuNPs/MWCNT/GCE displayed excellent electrochemical catalytic activities. The oxidation overpotentials of Tyr, AC and AA decreased significantly and their oxidation peak currents increased dramatically at AuNPs/MWCNT/GCE. DPV was used for the simultaneous determination of Tyr, AC and AA in their ternary mixture. Under the optimized experimental conditions Tyr, AC and AA give linear response over the range of 0.4-80.0 mu mol L-1, 0.09-35.0 mu mol L-1 and 1.0-150.0 mu mol L-1, respectively. The lower detection limits were found to be 0.21 for Tyr, 0.03 for AC and 0.76 mu mol L-1 for AA. The practical application of the modified electrode was demonstrated by measuring the concentration of Tyr, AC and AA in blood serum and pharmaceutical samples. (C) 2013 Elsevier B. V. All rights reserved.