Abbott Jeffrey, Ham Donhee, Xu Guangyu
School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.
Department of Electrical and Computer Engineering, University of Massachusetts, 100 Natural Resources Road, Amherst, MA, 01003, USA.
Methods Mol Biol. 2017;1572:169-187. doi: 10.1007/978-1-4939-6911-1_12.
Electrical sensing of biomolecules has been an important pursuit due to the label-free operation and chip-scale construct such sensing modality can enable. In particular, electrical biomolecular sensors based on nanomaterials such as semiconductor nanowires, carbon nanotubes, and graphene have demonstrated high sensitivity, which in the case of nanowires and carbon nanotubes can surpass typical optical detection sensitivity. Among these nanomaterials, graphene is well suited for a practical candidate for implementing a large-scale array of biomolecular sensors, as its two-dimensional morphology is readily compatible with industry standard top-down fabrication techniques. In our recent work published in 2014 Nature Communications, we demonstrated these benefits by creating DNA sensor arrays from chemical vapor deposition (CVD) graphene. The present chapter, which is a review of this recent work, outlines procedures demonstrating the use of individual graphene sites of the array in dual roles--electrophoretic electrodes for site specific probe DNA immobilization and field effect transistor (FET) sensors for detection of target DNA hybridization. The 100 fM detection sensitivity achieved in 7 out of 8 graphene FET sensors in the array combined with the alternative use of the graphene channels as electrophoretic electrodes for probe deposition represent steps toward creating an all-electrical multiplexed DNA array.
由于生物分子的电学传感具有无需标记的操作方式以及能够实现芯片级构建，因此一直是一个重要的研究方向。特别是基于半导体纳米线、碳纳米管和石墨烯等纳米材料的生物分子电传感器已展现出高灵敏度，就纳米线和碳纳米管而言，其灵敏度可超过典型的光学检测灵敏度。在这些纳米材料中，石墨烯非常适合作为实现大规模生物分子传感器阵列的实际候选材料，因为其二维形态很容易与行业标准的自上而下制造技术兼容。在我们于2014年发表在《自然·通讯》上的近期工作中，我们通过利用化学气相沉积（CVD）石墨烯创建DNA传感器阵列展示了这些优势。本章是对这项近期工作的综述，概述了一些程序，这些程序展示了如何将阵列中的单个石墨烯位点用于双重用途——作为用于位点特异性探针DNA固定的电泳电极以及作为用于检测目标DNA杂交的场效应晶体管（FET）传感器。阵列中8个石墨烯FET传感器中有7个实现了100 fM的检测灵敏度，再加上将石墨烯通道用作探针沉积的电泳电极，这些都朝着创建全电学多路复用DNA阵列迈出了步伐。
