多壁碳纳米管-十二烷基磺酸钠化学修饰电极在高浓度抗坏血酸体系中选择性测定多巴胺

研究了多巴胺(DA)在多壁碳纳米管-十二烷基磺酸钠(MWNTs-SDS)化学修饰电极上的伏安行为和在高浓度抗坏血酸(AA)体系中对多巴胺的选择性.将多壁碳纳米管-十二烷基磺酸钠(MWNTs-SDS)分散液滴加到处理过的电极表面制备生物传感器,以循环伏安法和示差脉冲伏安法研究多巴胺在MWNTs-SDS修饰电极上的电化学行为及其选择性.MWNTs-SDS修饰电极对多巴胺有显著的催化作用,在pH为6.0的磷酸盐缓冲溶液中,氧化峰电流值与多巴胺的浓度在4.0×10-7～3.8×10-5 mol/L和9.8×10-5～7.3×10-4 mol/L成线性关系,检测限为2.0×10-7 mol/L,MWNTs-SDS修饰电极具有响应快、灵敏度高、稳定性好、线性范围宽的性能,能在高浓度抗坏血酸体系中选择性测定多巴胺.

Selective Detection of Dopamine in the Presence of High-Concentration Ascorbic Acid Using Multi-wall Carbon Nanotubes-Sodium Dodecyl Sulfate Modified Glassy Carbon Electrode

Sodium dodecyl sulfate (SDS)/multi-wall carbon nanotubes (MWNTs) was dropped onto the surface of a glassy carbon electrode and the electrochemical characteristics of the modified electrode were studied. Compared with a bare electrode, the MWNTs-SDS modified electrode proved to have a high sensitivity and a good selectivity towards detecting dopamine (DA) in the presence of high-concentration ascorbic acid (AA). The oxidation peak current was proportional to the concentration of dopamine over the ranges from 4.0×10-7 mol/L to 3.8×10-5 mol/L and from 9.8×10-5 mol/L to 7.3×10-4 mol/L, and a detection limit of 2.0×10-7 mol/L was obtained.