Electrochemical response of dopamine at a penicillamine self-assembled gold electrode.
The penicillamine (Pen) self-assembled monolayer (SAM) modified gold electrode (Pen/Au) is demonstrated to catalyze the electrochemical response of dopamine (DA) by cyclic voltammetry. A pair of well-defined redox waves was obtained and the calculated standard rate constant (k(s)) is 3.88 x 10(-3) cm/s at the self-assembled electrode. The electrode reaction is a quasi-reversible process. The oxidation peak of DA can be used to determine the concentration of DA. The peak current and the concentration of DA are a linear relationship in the range of 2.0 x 10(-5) M to 8.0 x 10(-4) M. The detection limit is 4.0 x 10(-6) M. By ac impedance spectroscopy the apparent electron transfer rate constant (k(app)) of Fe(CN)(3-)/Fe(CN)(4-) at the Pen/Au electrode was obtained as 2.08 x 10(-5) cm/s. The Pen SAM was characterized with X-ray photoelectron spectroscopy (XPS), grazing angle FT-IR spectroscopy and contact angle goniometer.
Wang
Q
Q
Department of Chemistry, Peking University, Beijing 100871, People's Republic of China.
Dong
D
D
Li
N
N
D000818:Animals; D002384:Catalysis; D004298:Dopamine / Q000737:chemistry* / Q000378:metabolism; D004347:Drug Interactions; D004563:Electrochemistry; D004566:Electrodes; D006046:Gold; D006801:Humans; D007700:Kinetics; D010084:Oxidation-Reduction; D010396:Penicillamine / Q000737:chemistry* / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared; D013057:Spectrum Analysis; D014965:X-Rays
D006046:Gold; D010396:Penicillamine; D004298:Dopamine