【作者】 姜文净； 殷焕顺； 艾仕云；

【Author】 Wenjing Jiang;Hunshun Yin;Shiyun Ai;College of Chemistry and Material Science, Shandong Agricultural University;

【机构】 山东农业大学化学与材料科学学院；

【摘要】 电化学免疫传感器是将免疫分析与电化学传感技术相结合而构建的一类新型传感器。本文研究了一种利用石墨烯/四氧化三铁/β-环糊精（GO/Fe₃O₄/β-CD）纳米复合材料作为抗体载体,树状高分子/亲和素-碱性磷酸酯酶（PAMAM/avidin-ALP）作为信号分子,用于DNA甲基化的电化学分析方法。实验利用了5-甲基胞嘧啶与抗体的特异性反应,生物素与亲和素的特定反应,以及纳米复合材料进行信号扩增成功构建了生物免疫传感器并极大提高了反应的特异性。该生物免疫传感器对5-甲基胞嘧啶的检测呈现高灵敏度,检出限为0.033 nM,线性方程为I_pc （μA）=-2.082logc （nM）-3.4659。并利用该传感器分别对健康人、肝癌、乳腺癌患者体内的甲基化水平进行了研究并对比,进一步扩宽了制备的传感器的应用性。因此,本文所提出的电化学方法在甲基化的检测方面具有极大地潜力和实用价值。更多还原

【Abstract】 An ultrasensitive sandwiched electrochemical immunosensor was developed for 5 mC detection in genomic DNA by using β-cyclodextrin（β-CD） functionalized graphene oxide-magnetic nanocomposites（GO/Fe₃O₄/β-CD） as a immobilization matrix for anti-5 mC antibodies（Ab）, PAMAM conjugated avidin-ALP（PAMAM/avidin-ALP） as signal amplification unit.Importantly, the GO/Fe₃O₄/β-CD nanocomposites were verified to not only possess enormous surface for loading antibody by host-guest interaction, but also exhibit excellent electrical conductivity.With the dual signal amplification strategy, the electrochemical immunosensor showed wide detection range from 0.1 to 30 nM with low detection limit of 0.033 nM（S/N = 3）.Based on the specific immunoreaction, the developed method also illustrated excellent detection selectivity.The fabricated immunosensor was also applied to detect the 5 mC in genomic DNA of cancer tissue, which indicated that the immunosensor possess potential applications in clinical detection.更多还原