Analytical Sciences

Abstract − Analytical Sciences, 20(8), 1131 (2004).

Attachment of DNA to the Carbon Fiber Microelectrode via Gold Nanoparticles for Simultaneous Determination of Dopamine and Serotonin
Liping LU, Shuqing WANG, and Xiangqin LIN
Department of Chemistry, University of Science and Technology of China, Hefei, 230026, P. R. China
A novel biochemical sensor was fabricated on a carbon fiber microelectrode, which consisted of an inner layer of electrodeposited gold nanoparticles, as a nano-array electrode, and an outer layer of electrodeposited calf thymus ds-DNA at +1.5 V vs. SCE. This modified electrode was characterized by X-ray photoelectron spectroscopy, scanning electron microscope, atomic force microscopy, cyclic voltammetry and differential pulse voltammetry (DPV). It was found that this electrochemical sensor exhibits a strong catalytic activity toward the oxidation of dopamine (DA), serotonin (5-HT) and ascorbic acid (AA), as a result of resolving the anodic voltammetric peaks of DA, 5-HT and AA into three welldefined peaks. Simutaneous DPV determination of DA and 5-HT can be achieved in the presence of 2000-fold AA. The modified electrode shows good sensitivity, selectivity and stability.