%0 Journal Article %T Voltammetric Determination of Dopamine in Human Serum with Amphiphilic Chitosan Modified Glassy Carbon Electrode %A Cheng Yin Wang %A Zhi Xian Wang %A Ai Ping Zhu %A Xiao Ya Hu %J Sensors %D 2006 %I MDPI AG %R 10.3390/s6111523 %X An improvement of selectivity for electrochemical detection of dopamine (DA)with differential pulse voltammetry is achieved by covalently modifying a glassy carbonelectrode (GCE) with O-carboxymethylchitosan (OCMCS). The amphiphilic chitosanprovides electrostatic accumulation of DA onto the electrode surface. In a phosphate buffersolution (pH 6.0), a pair of well-defined reversible redox waves of DA was observed at theOCMCS/GCE with a ¦ÄEp of 52 mV. The anodic peak current obtained from thedifferential pulse voltammetry of dopamine was linearly dependent on its concentration inthe range of 6.0 ¡Á 10-8 to 7.0 ¡Á 10-6 M, with a correlation coefficient of 0.998. Thedetection limit (S/N = 3) was found to be 1.5 ¡Á 10-9 M. The modified electrode had beenapplied to the determination of DA in human serum samples with satisfactory results. %K O-carboxymethylchitosan %K chitosan %K dopamine %K voltammetry %K human serum %U http://www.mdpi.com/1424-8220/6/11/1523