Nafion修饰碳纤维纳米电极在抗坏血酸共存下选择性测定多巴胺

Nafion-Modified Carbon Fiber Nanoelectrode for Selective Detection of Dopamine in the Presence of Ascorbic Acid

采用电沉积法制备了Nafion修饰碳纤维纳米电极,利用扫描电子显微镜(SEM)表征了该修饰电极的表面形貌,采用差示脉冲伏安法(DPV)研究了多巴胺和抗坏血酸在该修饰电极上的电化学行为.结果表明:多巴胺和抗坏血酸在裸碳纤维电极上均能发生电化学反应,两氧化峰重叠.修饰电极对带负电的抗坏血酸有良好的屏蔽作用,可在1.0mmol/L高浓度抗坏血酸的共存下选择性测定多巴胺,峰电流与多巴胺浓度在1.0×10-7～1.0×10-4mol/L之间呈现良好的线性关系,检出限为1.0×10-8mol/L.该法有望用于检测活体中多巴胺浓度.

Carbon fiber nanoelectrode（CFNE） modified with Nafion was prepared by electrodeposition method.The surface morphology of modified electrode was observed by SEM.The electrochemical behaviour of dopamine（DA） and ascorbic acid（AA） with differential pulse voltammetry（DPV） on the modified electrode was investigated.The electrochemical experimental results showed that the bare electrode gave two oxidation peaks for DA and AA,and the oxidation peaks overlaped.As the electrochemical reaction of AA on the Nafion modified electrode does not occur for shielding effect,the modified electrode can be selectively used to detect DA without interference from high concentration AA.In the presence of 1.0 mmol/L AA,the oxidation peak current was linear with DA in the ranger of 1.0×10-7~1.0×10-4mol/L,and the detection limit was 1.0×10-8mol/L.The result indicated that the method is promising for the determination of DA in vivo.