Graphene based chemical and biological sensors

本研究计划旨在推进化学和生物传感应用中电活性纳米结构石墨烯器件的基础和应用研究。基于石墨烯的纳米结构是新型功能纳米结构材料中最强大的一类。石墨烯是一种真正的二维半金属材料，即使在室温下，电子也可以在几百纳米的范围内不散射地移动，更重要的是，它对局部环境非常敏感。该研究计划的核心将基于对化学和生物传感器的电响应的研究，这些传感器由(i)连接在石墨烯电极之间的受体位点和（ii）物理吸附在石墨烯薄片上的受体制成。该项目的第一部分(i)将基于一种有效的工艺，通过该工艺可以切割石墨烯片以产生分子尺度（~ 2nm）的间隙。石墨烯的端帽将被羧酸功能化，羧酸可用于与胺端分子线（桥）反应以重新连接电路。分子桥将为生物大分子、纳米粒子或小分子的附着引入一个反应位点。在第二部分（ii）中，我们将利用纳米管和纳米线传感器的最新发展。受体分子将通过芳香或多烯锚点的物理吸附附着在石墨烯上。靶标可以通过互补化学或引导自组装与这些位点结合。化学或生物传感器的电响应曲线将使用所要求的仪器进行测量。纳米制造方法将用于构建这些传感器，纳米制造过程将使用电传输、表面敏感技术和近端探针进行研究。提议的工作将结合有机化学，分子生物学，凝聚态物理，纳米材料科学和光谱学的元素。这项研究的结果将有助于指导基于石墨烯纳米结构材料的新检测方法的发展。

This research program aims to advance both the fundamental and applied study of electroactive nanostructured graphene devices for chemical and biological sensing applications. Graphene-based nanostructures are emerging as one of the most powerful classes of new functional nanostructured materials. Graphene is a truly two-dimensional semi-metallic material in which electrons can move without scattering for several hundred nanometers even at room temperature, and more importantly, it's very sensitive to the local environment. The core of this research program will be based on the investigation of the electrical responses of chemical and biological sensors made from (i) receptor sites wired between graphene electrodes, and from (ii) physically adsorbed receptors on graphene flakes. The first part (i) of this project will be based on an efficient process by which graphene sheets can be cut to create molecular-scale (~ 2 nm) gaps. The end cap of the graphene will be functionalized with carboxylic acids that can be used to react with amine-terminated molecular wires (bridges) to reconnect the circuits. The molecular bridges will introduce a reactive site for attachment of biological macromolecules, nanoparticles or small molecules. In the second part (ii), we will take advantage of recent developments in nanotube and nanowire based sensors. Receptor molecules will be attached to graphene through the physisorption of aromatic or polyene anchors. Targets could bind to these sites through complementary chemistry or by guided self-assembly. The electrical response curves of the chemical or biological sensors will be measured using the requested apparatus. Nanofabrication methods will be used to construct these sensors, and the nanofabrication process will be studied using electrical transport, surface sensitive techniques and proximal probes. The proposed work will combine elements of organic chemistry, molecular biology, condensed-matter physics, nanomaterial science, and spectroscopy. The results of this research will help guide the development of new detection methods based on graphene nanostructured materials.