Electrochemical Behavior and Determination of L ‐Tyrosine at Single‐walled Carbon Nanotubes Modified Glassy Carbon Electrode

Based on single‐walled carbon nanotubes (SWCNTs) modified glassy carbon electrode (GCE/SWCNTs), a novel method was presented for the determination of L ‐tyrosine. The GCE/SWCNTs exhibited remarkable catalytic and enhanced effects on the oxidation of L ‐tyrosine. In 0.10 mol/L citric acid‐sodium citrate buffer solution, the oxidation potential of L ‐tyrosine shifted negatively from +1.23 V at bare GCE to +0.76 V at GCE/SWCNTs. Under the optimized experimental conditions, the linear range of the modified electrode to the concentration of L ‐tyrosine was 5.0×10 −6 –2.0×10 −5  mol/L ( R 1 =0.9952) and 2.7×10 −5 –2.6×10 −4  mol/L ( R 2 =0.9998) with a detection limit of 9.3×10 −8  mol/L. The kinetic parameters such as α (charge transfer coefficient) and D (diffusion coefficient) were evaluated to be 0.66, 9.82×10 −5  cm 2 s −1 , respectively. And the electrochemical mechanism of L ‐tyrosine was also discussed.