Sapphire-supported nanopores for low-noise DNA sensing
Sapphire-supported nanopores for low-noise DNA sensing
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用于低噪声 DNA 传感的蓝宝石支撑纳米孔
DOI：
10.1016/j.bios.2020.112829
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发表时间：
2021
影响因子：
12.6
通讯作者：
Wang, Chao
中科院分区：
文献类型：
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作者：
Xia, Pengkun;Zuo, Jiawei;Paudel, Pravin;Choi, Shinhyuk;Chen, Xiahui;Rahman Laskar, Md Ashiqur;Bai, Jing;Song, Weisi;Im, JongOne;Wang, Chao
固态纳米孔传感器具有从单分子生物传感到诊断和测序的广泛应用。现有的纳米孔传感器通过微机械加工在硅（Si）衬底上制造，然而，由Si导电性引起的高电容噪声严重限制了它们的传感精度和记录速度。提出了一种新的方法，通过微图案化的三角形掩模对蓝宝石进行各向异性湿法刻蚀，在绝缘蓝宝石晶片上形成纳米孔膜。证明了平均尺寸为~10 μm的小膜的可重复形成。为了验证，具有比硅支撑（SiS）纳米孔大100倍的膜面积的硅支撑（SaS）纳米孔芯片显示出小130倍的电容（10 pF）和小~2.5倍的均方根（RMS）噪声电流（在100 kHz带宽上~20 pA）。使用1 kbp双链DNA进行测试，SaS纳米孔能够以微秒速度进行传感，信噪比为21，而SiS纳米孔为11。这种SaS纳米孔为生物传感以及各种MEMS应用提供了一个可行的可制造平台。
Solid-state nanopore sensors have broad applications from single-molecule biosensing to diagnostics and sequencing. Prevalent nanopore sensors are fabricated on silicon (Si) substrates through micromachining, however, the high capacitive noise resulting from Si conductivity has seriously limited both their sensing accuracy and recording speed. A new approach is proposed here for forming nanopore membranes on insulating sapphire wafers by anisotropic wet etching of sapphire through micro-patterned triangular masks. Reproducible formation of small membranes with an average dimension of ~10 μm are demonstrated. For validation, a sapphire-supported (SaS) nanopore chip, with a 100 times larger membrane area than silicon-supported (SiS) nanopore, showed 130 times smaller capacitance (10 pF) and ~2.5 times smaller rootmean-square (RMS) noise current (~20 pA over 100 kHz bandwidth). Tested with 1k bp double-stranded DNA, the SaS nanopore enabled sensing at microsecond speed with a signal-to-noise ratio of 21, compared to 11 from a SiS nanopore. This SaS nanopore presents a manufacturable platform feasible for biosensing as well as a wide variety of MEMS applications.