Electrochemical Sensor Based on Single-Walled Carbon Nanotubes-Modified Gold Electrode for Uric Acid Detection.

A selective and sensitive electrochemical sensor for detecting uric acid (UA) has been developed. The UA electrochemical sensor was made from single-walled carbon nanotubes (SWCNTs), which were coated on the surface of a gold wire electrode using the chemical vapor deposition (CVD) method. The performance of UA electrochemical sensor was characterized using cyclic voltammetry. The obtained calibration curve followed a linear equation, i_pa = 132.753 + 1.512c, with R² = 0.99597. The LOD and sensitivity of the SWCNTs-modified gold electrode for UA detection obtained were 5.05 nM and 5.240 μA mm^-2nM^-1, respectively. The reaction between the electrode and UA demonstrated the diffusion-controlled behavior. No interference signals from ascorbic acid, glucose and urea were observed during the UA measurements. However, the signal for dopamine appeared in the voltammogram, although it was located at a different potential. Moreover, the dopamine signal disappeared when the measurement was conducted at concentrations of less than 1 mM. These results confirm that SWCNTs-modified gold electrodes are favorable for detecting uric acid. [ABSTRACT FROM AUTHOR]