基于石墨烯手性放大效应构筑的电位识别对映体的新方法研究

For overcoming the bottleneck of development of chiral potential sensing, based on excellent graphene as chiral amplification material, and molecularly imprinted polymers with high efficiency and specificity as selectors, chiral potential sensors will be constructed by means of graphene hybrided molecularly imprinted polymers in this proposal. Setting up a potential identification scale, and a qualitative and semi-quantitative method based on the electrochemical oxidation/reduction peak potential will be established to quickly identify the enantiomer and determine their ratio. The fabrication of chiral interface of graphene hybrided molecularly imprinted membrane, aims at enlarging the oxidation/reduction peak potential difference of two enantiomers (D- and L-) on the sensor, resulting in greatly improving the sensitivity of potential recognition of enantiomers. Furthermore, the structure - activity relationship among graphene, molecularly imprinted membrane and oxidation/reduction potential difference of enantiomers will be studied in this proposal, and a binding sites model for enatiomers based on the graphene hybrided molecularly imprinted sensing membrane will be obtained. The chiral amplification mechanism of the synergy effect between graphene and molecularly imprinted polymer will also be investigated by means of computer simulation and quantitative calculation, and the main design ideas for the potential sensing of the graphene-imprinted membrane are expected to be obtained. The constructed chiral potential sensors can be employed for fast and sensitive monitoring the ratio of enantiomers (such as amino acids). Furthermore, the micro-nano sensors based on potential/current double response will also be developed, and can be employed for on-line monitoring some chiral disease markers. Therefore, this proposal can provide a novel method and warning device for the early diagnosis of serious disease.

为突破手性电位传感发展的瓶颈问题，本课题提出籍性能优异的石墨烯作为手性信号放大材料，以高效、专一的分子印迹聚合物作为传感器手性选择体，构筑石墨烯杂化的印迹聚合物电位型手性传感器；创新性设立电位识别标尺，建立一种依据电化学氧化/还原峰电位来快速识别对映体组分及其比例的定性、半定量新方法。石墨烯杂化的印迹膜手性界面的构建，旨在增大两对映异构体在传感器上的氧化/还原峰电位差，极大提高电位识别对映体的灵敏度和选择性。课题将阐明石墨烯-印迹膜-电位识别对映体组分间的构-效关系，给出石墨烯杂化的分子印迹传感膜的结合位点模型；采用计算机模拟和量化计算探求石墨烯协同分子印迹聚合物的手性放大机理，以期得到传感膜设计要义。所构建的电位识别新方法，可用于对映体(如氨基酸等)组分及比例的快速、灵敏检测；尝试发展电位/电流双响应型微纳手性传感器，在线监测手性疾病标志物，为重大疾病的早期诊断与预警提供新方法和新器件。

自然界中手性对映体无所不在，相同的理化性质却存在着生理代谢、药理活性、及病理毒性等巨大差异。因此，高效、精准的手性识别对临床、制药、生化科学等尤为重要。电化学伏安法凭借高灵敏、简便直观、廉价快速的优势被广泛用于新型电流/电位响应手性识别传感器。但受限于对映体极强的相似和有限的识别材料等因素，手性拆分的实际检测仍然面临着艰巨挑战。对此，解决问题的关键是寻找新型手性传感膜材料，实现对映体传感上的电化学特征峰电流/电位差信号扩增，从而突破手性识别传感器的发展瓶颈，建立电位识别对映体新策略。新型复合膜材料兼容分子印迹聚合物(MIPs)、金属有机框架(MOFs)和环糊精的选择性识别能力，及碳/金属纳米材料的信号增敏性能，激发了协同扩增效应，最大化对映体的电化学响应差异。借助各种表征手段和量子化学模拟，探究了电位手性识别的构效关系和理论支撑。据此，课题创新性地建立了多种手性氨基酸/药物分子的电流/电位手性识别分析和半定量比例传感新技术。进一步利用复合膜集成的阻抗传感技术，拓展到弱/非电化学活性物质的手性识别。详列研究内容和结果如下：.1..成功复合多种MIPs与还原氧化石墨烯，协同放大对映体的电位差异，建立简便灵敏的对映体电位识别比例尺与电流/电位定量策略，并实现S-普萘洛尔，酪氨酸，苯丙氨酸，色氨酸等的快速手性识别。.2..基于纳米基/环糊精/MOFs等材料构建微纳手性电位识别体系，攻克弱电活性物质的检测壁垒，拓宽电位识别法的普适性(多种材料均实现100 mV级别电位差)，实现多巴(难拆分对映体)及若干弱电活性氨基酸的有效电化学传感。.3..开发复合传感膜修饰的手性识别阻抗响应新体系，实现半胱氨酸及天冬氨酸等弱/非电活性手性待测氨基酸的快速定量检测。.4..原理探究：整合光/电/显微镜等表征手段，论证传感器识别材料与手性分子的构效关系，量子化学建模理论推演两者的分子交互作用，以此初步阐明手性识别机制。