多巴胺在电沉积石墨烯修饰碳分子线电极上的电化学测定

Electrochemical Detection of Dopamine on Electrodeposited Graphene Modified Carbon Molecular Wire Electrode

以分子线二苯乙炔为修饰剂和粘合剂制备了一种新型的碳糊电极-碳分子线电极（CMWE）,并以其为基底电极采用电化学还原法将石墨烯（GR）沉积到CMWE表面得到电沉积石墨烯修饰碳分子线电极（GR/CMWE）。考察了多巴胺（DA）在该修饰电极上的电化学行为。实验结果显示DA在GR/CMWE上出现了1对峰形良好的氧化还原峰,与裸电极相比,该氧化还原峰的电流增大,峰电位差减小,表明修饰电极对DA的电化学反应有催化作用。在最佳实验条件下峰电流与DA浓度在8.0×10-7-2.0×10-3 mol/L范围内呈良好的线性关系,检出限（3σ）为2.55×10-7 mol/L。将该电极用于多巴胺注射液样品的检测,结果满意。

By using a kind of molecular wire diphenylacetylene as the modifier and the binder,a new carbon paste electrode,which was denoted as carbon molecular wire electrode（CMWE）,was prepared and used as the substrate electrode.Then graphene（GR） was electrodeposited on the surface of CMWE to get the modified electrode named as GR/CMWE.The electrochemical behaviors of dopamine（DA） on GR/CMWE were investigated by cyclic voltammetric method.A pair of the well-defined redox peaks were observed.Compared with that of CMWE,the redox peak currents increased greatly with the decrease of the peak-to-peak difference,indicating that the electrode reaction of DA on GR/CMWE was reversible.Under the optimal conditions,the peak currents had a good linear relationship with DA concentration in the range of 8.0×10-7 - 2.0×10-3 mol/L with a detection limit（3σ） of 2.55×10-7 mol/L.The commonly coexisting substances did not interfere DA detection, and the proposed method was applied in the determination of DA in injection samples with satisfactory results.