An inlaying ultra-thin carbon paste electrode modified with functional single-wall carbon nanotubes for simultaneous determination of three purine derivatives

A functional single-wall carbon nanotube film electrode (SWNTE) was constructed on the surface of inlaying ultra-thin carbon paste electrode (IUTCPE). The precursor film was formed by direct inlaying carbon paste onto nichrome substrate. Scanning electron microscope (SEM) was employed to characterize the electrode surface. The electrochemical behavior of SWNT/IUTCPE for xanthine (Xa), hypoxanthine (Hxa) and uric acid (UA) was investigated by various electrochemical techniques. The SWNT/IUTCPE exhibited an excellent electrocatalysis and enhancement of the current response for the purine derivatives. Three well-defined oxidation peaks of Xa, Hxa and UA were appeared at the electrode. The proposed electrode can be applied to determine Xa, Hxa and uric acid in human urine simultaneously without any pretreatment.