Analytical Sciences

Abstract − Analytical Sciences, 24(12), 1563 (2008).

Sensitive Determination of Dopamine and Uric Acid by the Use of a Glassy Carbon Electrode Modified with Poly(3-methylthiophene)/Gold Nanoparticle Composites
Xue HUANG, Yongxin LI, Po WANG, and Lun WANG
Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, P. R. China
A kind of novel nanocomposites, poly(3-methylthiophene) (P3MT)/gold nanoparticles (AuNPs), were successfully deposited onto the surface of a glassy carbon electrode. A field emission scanning electron microscope (FE-SEM) and electrochemical techniques were used for characterizing this modified electrode. The results showed that the AuNPs were inserted into a P3MT layer uniformly, and formed a porous 3D structure. This modified electrode showed excellent electrocatalytic activity towards the oxidation of ascorbic acid (AA), dopamine (DA) and uric acid (UA); the overlapping anodic peaks of AA, DA and UA were completely divided into three well-defined voltammetric peaks. A further study showed that there existed a linear relationship between the peak current and the concentration of DA in the range of 1.0 × 10-6 to 3.5 × 10-5 mol L-1, and UA in the range of 1.0 × 10-6 to 3.2 × 10-5 mol L-1. The detection limits were 2.4 × 10-7 mol L-1 for DA and 1.7 × 10-7 mol L-1 for UA. This proposed method was applied to the detection of real samples, and the results were satisfactory.