Characteristics of a Poly(thionine) Modified Glassy Carbon Electrode and the Detection of Dopamine and Uric acid

摘要

A simple and sensitive electrochemical sensor for the simultaneous detection of dopamine (DA) anduric acid (UA) in the presence of ascorbic acid (AA) was developed, based on the poly(thionine)(PTH) modified glassy carbon electrode (GCE). The PTH/GCE sensor could clearly separate theelectro-oxidation signals of DA and UA from that of AA. The accumulated surface charges of the PTHfilm and pH of the base solutions were optimized for improved simultaneous quantitative detection ofDA and UA. The oxidation peak currents of DA and UA were both linear over the range from 5 to 302 M in the presence of 200 M AA. The sensor showed sensitivities of 22.87 and 6.02 /cm /with detection limits (S/N=3) of 0.7 and 1.3 M for DA and UA, respectively. The sensor obtainedinterference free signals and excellent recoveries from spiked human urine samples for both DA andUA detection.