聚多巴胺-还原氧化石墨烯修饰电极同时测定邻苯二酚和对苯二酚

Simultaneous Detection of Catechol and Hydroquinone by PDA-rGO Modified Electrode

制备了聚多巴胺-还原氧化石墨烯修饰玻碳电极(PDA-rGO/GCE),以此修饰电极作为工作电极,采用循环伏安法(CV)对邻苯二酚(CC)和对苯二酚(HQ)的电化学行为进行了研究。结果表明CC和HQ在该修饰电极上的峰电流与氧化石墨烯修饰电极相比有了明显增高,并且它们的氧化峰电位差和还原峰电位差均超过110 mV,证明该修饰电极用于两种酚的同时检测是可行的。在优化实验条件下,采用微分脉冲伏安法(DPV)对CC和HQ同时进行检测,CC和HQ的峰电流与其浓度均在1.0×10-6~4.0×10-3 mol/L范围内呈良好的线性关系,检出限(S/N=3)分别为2.0×10-7 mol/L和3.6×10-7 mol/L。以所制备的修饰电极对自来水水样和湖水水样进行了加标回收检测,回收率在97.6%~100.6%范围内。

Reduced graphene oxide was prepared with dopamine as the reductant,and this method is convenient,mild and low-cost.The as-prepared polydopamine-reduced graphene oxide was modified onto the glassy carbon electrode via drop-coating method.As an electrode modification material with the advantages of high electron conduction efficiency and good chemical stability,reduced graphene oxide has been widely used in the detection of various samples.Using the polydopamine-reduced graphene oxide modified electrode,the electrochemical behavior of catechol and hydroquinone were explored by cyclic voltammetry.The results showed that the peak currents of the two dihydroxybenzenes were higher than that at graphene oxide modified electrode.Also,both of the oxidation and reduction peak potential differences between catechol and hydroquinone exceeded 110 mV,which was sufficient to distinguish the two isomers.Under optimum conditions,the peak currents obtained with differential pulse voltammetric determination showed good linear relationships with concentrations of catechol and hydroquinone in the range from 1.0×10-6-4.0×10-3 mol/L with detection limits of 2.0×10-7 mol/L and 3.6×10-7 mol/L(S/N=3),separately.And the recovery rates of the spiked tap water and lake water were also in satisfied range.