氧化石墨烯-连续鸟嘌呤碱基DNA复合膜修饰电极用于测定多巴胺  

Graphene Oxide-Consecutive Guanine DNA Composite Membrane Modified Electrode for Determination of Dopamine

作　　者：秦至臻 刘兴华 陈斌 康维钧[1] 牛凌梅[1] QIN Zhizhen;LIU Xinghua;CHEN Bing;KANG Weijun;NIU Lingmei(School of Public Health,Hebei Medical University,Shijiazhuang 050017,China;College of Pharmacy,Hebei Medical University,Shijiazhuang 050017,China)

机构地区：[1]河北医科大学公共卫生学院,石家庄050017 [2]河北医科大学药学院,石家庄050017

出　　处：《理化检验（化学分册）》2018年第12期1394-1399,共6页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：国家自然科学基金(81402720);河北省杰出青年基金(H2016206557)

摘　　要：移取1g·L^(-1)氧化石墨烯悬浮液5μL滴加在经抛光、清洗的玻碳电极表面,红外灯下烘干后,在0.1mol·L^(-1) KH2PO4溶液中,在-0.9V下沉积600s,然后将电极浸泡于100μmol·L^(-1)连续鸟嘌呤碱基DNA溶液中1h,得到氧化石墨烯-连续鸟嘌呤碱基DNA复合膜修饰电极。采用透射电子显微镜、扫描电子显微镜和电化学方法对修饰电极进行了表征,研究了多巴胺在此修饰电极上的电化学行为,结果发现此修饰电极对多巴胺的氧化还原具有明显的电催化作用。在pH 7.0的磷酸盐缓冲溶液中,以50mV·s-1的扫描速率扫描,记录多巴胺在修饰电极上的差分脉冲伏安曲线,结果发现多巴胺的浓度在5.0×10^(-7)～9.0×10^(-6) mol·L^(-1),9.0×10^(-6)～5.0×10^(-5) mol·L^(-1)内与其氧化峰电流呈线性关系,检出限(3s/k)为3.5×10-8 mol·L^(-1)。方法可用于测定体液和药品中多巴胺的含量,加标回收率在88.0%～106%之间,测定值的相对标准偏差(n=5)小于5.0%。5μL of 1g·L^-1 graphene oxide solution was dipped onto the surface of the polished and cleaned glassy carbon electrode.After dring under infrared light,the electrode was deposited in a 0.1 mol·L^-1 KH2PO4 solution at -0.9V for 600s.Then the electrode was immersed in 100μmol·L^-1continuous guanine DNA solution for 1h to obtain a graphene oxide-continuous guanine DNA composite membrane modified electrode.The modified electrode was characterized by transmission electron microscopy,scanning electron microscopy and electrochemical method.The electrochemical behavior of dopamine at the modified electrode was studied.It was found that the modified electrode showed obvious electrocatalytic effect on the redox of dopamine.In phosphate buffer solution(pH 7.0),the differential pulse voltammograms of dopamine at the modified electrode were recorded at a scan rate of 50mV·s^-1.Linear relationships were found between the oxidation peak current and the concentration of dopamine in the ranges of 5.0×10^-7-9.0×10^-6mol·L^-1,9.0×10^-6-5.0×10^-5 mol·L^-1,respectively,and the detection limit(3s/k)was 3.5×10^-8mol·L6^-1.The method was used for determining the content of dopamine in body fluids and medicines,giving values of recovery obtained by standard additiom method between 88.0%and 106%,and RSDs(n=5)less than 5.0%.

关 键 词：氧化石墨烯 连续鸟嘌呤碱基DNA 修饰电极 多巴胺 差分脉冲伏安法 

分 类 号：O657.1[理学—分析化学]