Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
Sci Rep. 2011;1:46. doi: 10.1038/srep00046. Epub 2011 Jul 28.
Electrode-embedded nanopore is considered as a promising device structure for label-free single-molecule sequencing, the principle of which is based on nucleotide identification via transverse electron tunnelling current flowing through a DNA translocating through the pore. Yet, fabrication of a molecular-scale electrode-nanopore detector has been a formidable task that requires atomic-level alignment of a few nanometer sized pore and an electrode gap. Here, we report single-molecule detection using a nucleotide-sized sensing electrode embedded in-plane nanopore. We developed a self-alignment technique to form a nanopore-nanoelectrode solid-state device consisting of a sub-nanometer scale electrode gap in a 15 nm-sized SiO(2) pore. We demonstrate single-molecule counting of nucleotide-sized metal-encapsulated fullerenes in a liquid using the electrode-integrated nanopore sensor. We also performed electrical identification of nucleobases in a DNA oligomer, thereby suggesting the potential use of this synthetic electrode-in-nanopore as a platform for electrical DNA sequencing.
电极嵌入纳米孔被认为是一种有前途的无标记单分子测序的器件结构，其原理是基于通过穿过孔的 DNA 横向电子隧穿电流来识别核苷酸。然而，制造分子级的电极-纳米孔探测器一直是一项艰巨的任务，需要几纳米大小的孔和电极间隙的原子级对准。在这里，我们报告了使用嵌入平面纳米孔的核苷酸大小的传感电极进行单分子检测。我们开发了一种自对准技术，形成了由亚纳米级电极间隙组成的纳米孔-纳米电极固态器件，该电极间隙位于 15nm 大小的 SiO(2)孔中。我们使用电极集成纳米孔传感器在液体中对核苷酸大小的金属封装富勒烯进行了单分子计数。我们还对 DNA 寡聚物中的核碱基进行了电识别，从而表明这种合成电极-纳米孔作为电 DNA 测序平台的潜力。
