石墨烯-有机共轭分子纳米墙与纳米线电极直接、自由转换检测不同靶基因的比较研究

In this project, novel graphene-organic conjugated molecule nanowall and nanowire electrodes, which possess rich-conjugated structures, plenty of electrochemical sites, and super conductivity, will be carried out for direct, highly sensitive, and freely switchable detection of different target genes originated from real sample of the transgenic plants. Chemical and electrochemical routes will be adopted to prepare a series of nanowall and nanowire nanocomposites, which integrate graphene (a single-atom thick, two-dimensional sheet of sp2 bonded conjugated carbon) with organic conjugated molecule (owning rich-conjugated structures, functional groups, and excellent electrochemical activity). We will study the effect of different preparation schemes and experimental parameters on the morphology, size, and electrochemical signals of the nanocomposites. The immobilization of the probe DNA will be mainly conducted via noncovalent methods (for freely switchable detection) due to π-π interaction between conjugated nanocomposites and DNA bases. The hybridization between the probe DNA and target DNA induces the formation of dsDNA. The resulted dsDNA will release from conjugated nanocomposites, accompanied with the self-signals changes of nanocomposites (signal-on and signal-off). The self-signals changes will serve as a powerful tool to investigate the effect of different morphology, clearance, sizes of nanowall and nanowire electrodes on the loading of the probe DNA, hybridization efficiency, sensitivity, recovery of sensing platform. The synergistic effect of graphene-organic conjugated molecule nanowall and nanowire electrodes improving the sensitivity for the target DNA detection will be pursued. Above nanocomposites will be adopted to detect the gene sequences originated from real sample of the different transgenes of the transgenic plants integrated with gene amplification.

本项目拟构建新颖的石墨烯-有机共轭分子纳米墙与纳米线，其具有丰富的共轭结构、大量电活性位点与优异导电性能可实现直接、高灵敏、自由转换检测转基因植物产品不同靶基因。利用石墨烯特性（如二维共轭单原子层）和有机共轭分子特性（丰富的共轭结构、各种特色功能团、优异电化学活性），采用化学法和电化学法设计一系列复合纳米墙、线界面，对比各种制备方案、实验参数对界面形貌、尺寸、电化学信号等的影响。借助共轭界面与DNA碱基相互作用，实现DNA在电极表面有效非共价固定（后续自由转换检测的基础）；探讨纳米界面自身电化学性质受DNA固定与杂交的影响（"信号开、关"）；对比研究不同形貌、间隙、尺度纳米墙与纳米线电极在DNA固定、杂交效率、灵敏度以及再生性能的差异，研究石墨烯-有机共轭分子纳米结构电极协同改善传感器分析性能的机理及规律。将制备的电化学传感器直接、高灵敏、自由转换检测转基因植物产品的不同靶基因片断。

本项目围绕构建新颖的自身电化学性能优异的石墨烯-有机共轭分子纳米墙和纳米线电极并应用于直接、高灵敏、自由转换电化学检测不同靶标开展多方面的研究。可控制备了新颖的石墨烯-有机共轭分子纳米材料，借助超分子组装、化学键合与电化学沉积等方式成功构建一系列新颖的一维与二维有机共轭分子传感界面，比较传感界面的维度、尺度、空间取向、间隙等因素对电极自身电化学、DNA固定、杂交效率、灵敏度以及再生性能的影响，详细研究界面物理与化学性质尤其是电化学信号、DNA固定与DNA杂交三者关系，取得杂交信号的最大化，最终实现高灵敏度、免标记、普适性的DNA杂交识别。在国内外高水平学术期刊如ACS Appl Mater Inter, Anal Chem, Biosens Bioelectron, J Mater Chem B, J Phys Chem C等上面发表和接受发表了34篇SCI论文（均标明基金资助）。其中影响因子大于5的11篇，一二区28篇，这些文章目前为止被Chem Soc Rev, Nano Today, Biosens Bioelectron, Anal Chem 等国际权威、重要刊物他引220余次。获第十届青岛市青年科技奖，山东省2014年度科学技术奖(自然科学类)二等奖（第二位），山东省2014年度高等学校优秀科研成果二等奖（第一位），作为指导老师获山东省2015年度研究生优秀科技创新成果一等奖。培养硕士研究生15人，其中9人已获得硕士学位。