间氨基苯酚修饰玻碳电极测定多巴胺
Determination of Dopamine at m-Aminophenol Modified Glassy Carbon Electrode
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摘要: 玻碳电极在含有2.0 mmol·L-1间氨基苯酚的0.1 mol·L-1的三水合高氯酸锂溶液中,于0~1.5 V的电位范围内进行电化学修饰,制备了间氨基苯酚修饰电极(m-AP/GCE).研究发现:间氨基苯酚修饰电极对多巴胺有良好的电催化作用,多巴胺在该电极上出现了一对氧化还原峰,相对于裸玻碳电极,氧化还原峰电位差为减至70 mV,提出了用循环伏安法测定多巴胺的方法.氧化峰电流与多巴胺的浓度在1.2×10-7~9.1×10-6和9.1×10-6~1.2×10-4mol·L-1范围内呈线性关系,检出限(3S/N)为3.2×10-8mol·L-1.Abstract: The glassy carbon electrode (GCE) was modified electrochemically on its surface with m-aminophenol (m-AP) in 0.1 mol·L-1 LiClO4 solution containing 2.0 mmol·L-1 m-AP at the potential of 0~1.5 V.This modified electrode described above was named abbreviately as m-AP/GCE.It was found that significant catalytic action of the m-AP/GCE was observed on the reaction of dopamine (DA) at the electrode.DA showed a pair of oxidation peak and reduction peak at m-AP/GCE,with potential difference of oxidation peak and reduction peak reduced to a value of 70mV as compared with its reaction at the bare GCE.Based on these findings,a selective method for determination of DA by cyclic voltammetry was proposed.Linear relationships between values of oxidation peak current and concentration of DA were obtained in the ranges of 1.2×10-7-9.1×10-6 and 9.1×10-6-1.2×10-4mol·L-1,with detection limit (3S/N) of 3.2×10-8mol·L-1.
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