石墨烯π-堆叠效应诱导的“糖电极”简易自组装及其生物传感

The intercellular recognition between cell surface-attached carbohydrates and transmenbrane carbohydrate-recognition proteins (lectins) initiates a range of central biological and pathological events including cell-cell adhesion, cell differentiation, endocytosis, immunoresponse, cancer metastasis and virus invasion. Therefore the ingenious detection of such carbohydrate-lectin interactions is crucial for the delineation of the "glycomics" and the development of early-state diease diagnosis. This project employs graphene, a C-sp2-hybridized, one-atom-thick planar and benign electric material as the medium for the unprecedented realization of π-stacking-mediated self-assembly of triazolyl antraquinonyl glycosides synthesized via the higly efficient and stereoselective click reaction to screen printed electrodes composed of graphite. These functionalized electrodes will be used for the detection of specific carbohydrate-lectin interactions via electrochemical methods such as differential pulse votammetry and impedance spectroscopy. A further probing of the cell line that overexpresses specific lectins will also be tentatively actualized in using the "glycosylated" graphene-based electrodes. This project would consequently lead to a novel, readily available, economical yet sensitive and bio-selective electrochemical platform toward the study of the "glycomics" as well as the development of diagnoses of early-state desease.

细胞表面附着糖链与其特异糖识别蛋白（凝集素）的相互作用启动了一系列重要生物及病理学历程，如细胞的黏附和分化、细胞内吞、免疫应答及癌转移和病毒入侵。因而对于糖-凝集素间特异识别的检测被认为有助于"糖组学"解译和疾病早期诊断的发展。本项目首次以石墨烯，这一由碳sp2轨域混杂的良好平整导电材质为媒介，将与蒽醌偶联的各种糖分子经π-堆叠效应附着于石墨印刷电极，并通过电化学表征其与特异凝集素间的响应。应用"点击反应"这一高效、高立体选择性的键合手段将炔基蒽醌与系列叠氮糖分子偶联，其中蒽醌不但充当电活性"报告团"，还可与石墨烯进行π-π堆叠。随后将"糖基化"的石墨烯附着于石墨电极，联用电化学伏安和阻抗方法区分其与特异和非特异凝集素间的识别响应，并进一步实现细胞间糖-凝集素识别的生物传感。这一经石墨烯介导简易构建的"糖电极"体系可为"糖组学"研究和早期疾病诊断提供一类新颖高效的经济型电化学检测平台。

癌细胞的快速、准确发现与捕获是当前生命科学领域亟待攻克的世界性难题。本项目通过石墨烯自组装技术构建了芘撑糖醌石墨烯电化学传感电极，并实现了表达不同糖识别受体的疾病细胞检测，进一步拓展了糖基石墨烯荧光复合材料，实现了疾病细胞的受体靶向标记。在Adv. Mater., Adv. Funct. Mater., Chem. Sci., Small, Chem. Commun.等期刊上发表SCI文章10篇，申请专利2项。本项目研究为癌细胞的便捷式检测与标记提供了新的技术手段。