Indicator-free electrochemical genosensing originated from the self-signal of poly-xanthurenic acid enhanced by Fe3O4/reduced graphene oxide
Indicator-free electrochemical genosensing originated from the self-signal of poly-xanthurenic acid enhanced by Fe3O4/reduced graphene oxide
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DOI：
10.1007/s10008-014-2487-y
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发表时间：
2014-05
影响因子：
2.5
通讯作者：
Wei Zhang;Libin Wang;Xiuwen Zheng
中科院分区：
文献类型：
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作者：
Wei Zhang;Libin Wang;Xiuwen Zheng
基于Fe 3 O 4/还原氧化石墨烯（Fe 3 O 4/RGO）增强聚黄尿酸（PXa）自身信号变化，构建了一种无指示剂的电化学基因传感平台。通过透射电子显微镜、循环伏安法和电化学阻抗谱（EIS）对所得纳米复合材料（PXa-Fe 3 O 4/RGO）进行了表征。共轭Fe 3 O 4/GO与黄尿酸单体芳环之间的π-π* 堆积和氢键作用促进了PXa的电聚合效率，并提高了PXa的电化学响应。利用PXa-Fe_3 O_4/RGO共轭纳米结构与DNA碱基之间的π-π ~* 相互作用，通过非共价法成功实现了特异性探针DNA的固定。探针DNA和靶DNA之间的杂交诱导所产生的双链（ds）DNA从缀合的纳米复合材料释放，伴随着纳米复合材料的自信号再生（“信号开启”）。这种自信号变化可以作为一种强有力的工具，用于无指示剂和自由切换检测不同的靶基因，并且集成的石墨烯基纳米复合材料的协同效应有效地提高了通过EIS检测靶DNA的灵敏度。
In this paper, an indicator-free electrochemical genosensing platform based on the self-signal changes of poly-xanthurenic acid (PXa) enhanced by Fe3O4/reduced graphene oxide (Fe3O4/RGO) was constructed. The resulting nanocomposite (PXa-Fe3O4/RGO) was characterized by transmission electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The π–π* stacking and hydrogen bonding between the conjugated Fe3O4/GO and aromatic ring of xanthurenic acid monomer promoted the electropolymerization efficiency accompanied with an increased electrochemical response of PXa. The immobilization of the specific probe DNA was successfully realized via the noncovalent method due to the π–π* interaction between the conjugated nanostructure of PXa-Fe3O4/RGO and DNA bases. The hybridization between the probe DNA and target DNA induced the resulted double-stranded (ds)DNA to be released from the conjugated nanocomposite, accompanied with the self-signal regeneration of nanocomposite (“signal-on”). The self-signal changes could serve as a powerful tool for indicator-free and freely switchable detection of different target genes, and the synergistic effect of the integrated graphene-based nanocomposite effectively improved the sensitivity for the target DNA detection via EIS.