Ma Xin-ying, Chao Zhi, Li Xia, Xu He-yun, Zhang Guo-rong
Department of Chemistry, Heze University, Heze 254015, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2006 May;26(5):648-50.
To establish an assay system for determination of dopamine (DA) in the presence of ascorbic acid (AA) with L-cysteine modified glassy carbon electrode.
L-cysteine was modified onto glassy carbon electrode electrochemically, and with this modified electrode, dopamine was determined by linear sweep stripping voltammetry.
L-cysteine polymer-modified electrode had strong catalytic effect towards the electrochemical oxidation of DA. The modified electrode showed good properties in determination of DA with coexisting AA. Under selected conditions, the linearity of DA was in the range of 2.0 x 10(-7) - 1.0 x 10(-4) mol/L with the detection limit of 2.0 x 10(-8) mol/L. The stability, reliability and recovery of this L-cysteine-modified electrode based on electrochemical method were also satisfactory.
L-cysteine-modified electrode can avoid the interference by AA for determination of DA.
建立一种在抗坏血酸（AA）存在下用L-半胱氨酸修饰玻碳电极测定多巴胺（DA）的检测系统。
通过电化学方法将L-半胱氨酸修饰到玻碳电极上，并用该修饰电极通过线性扫描溶出伏安法测定多巴胺。
L-半胱氨酸聚合物修饰电极对DA的电化学氧化具有较强的催化作用。该修饰电极在共存AA的情况下测定DA表现出良好的性能。在选定条件下，DA的线性范围为2.0×10⁻⁷ - 1.0×10⁻⁴ mol/L，检测限为2.0×10⁻⁸ mol/L。基于电化学方法的这种L-半胱氨酸修饰电极的稳定性、可靠性和回收率也令人满意。
L-半胱氨酸修饰电极可避免AA对DA测定的干扰。
