Nanopore sensing is a powerful tool for the detection of biomolecules. Solid-state nanopores act as single-molecule sensors that can function in harsh conditions. Their resilient nature makes them attractive candidates for taking this technology into the field to measure environmental samples for life detection in space and water quality monitoring. Here, we discuss the fabrication of silicon nitride pores from ∼1.6 to 20 nm in diameter in 20-nm-thick silicon nitride membranes suspended on glass chips and their performance. We detect pure laboratory samples containing a single analyte including DNA, BSA, microRNA, TAT, and poly-D-lys-hydrobromide. We also measured an environmental (mixed-analyte) sample, containing Antarctic dirt provided by NASA Ames. For DNA measurements, in addition to using KCl and NaCl solutions, we used the artificial (synthetic) seawater, which is a mixture of different salts mimicking the composition of natural seawater. These samples were spiked with double-stranded DNA (dsDNA) fragments at different concentrations to establish the limits of nanopore sensitivity in candidate environment conditions. Nanopore chips were cleaned and reused for successive measurements. A stand-alone, 1-MHz-bandwidth Chimera amplifier was used to determine the DNA concentration in artificial seawater that we can detect in a practical time scale of a few minutes. We also designed and developed a new compact nanopore reader, a portable read-out device with miniaturized fluidic cells, which can obtain translocation data at bandwidths up to 100 kHz. Using this new instrument, we record translocations of 400 bp, 1000 bp, and 15000 bp dsDNA fragments and show discrimination by analysis of current amplitude and event duration histograms.

中文翻译：

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使用氮化硅纳米孔检测单一分析物和环境样品：人工海水中的南极污垢颗粒和 DNA

纳米孔传感是检测生物分子的有力工具。固态纳米孔充当单分子传感器，可以在恶劣条件下工作。它们的弹性特性使它们成为有吸引力的候选者，可以将这项技术带入该领域，以测量环境样本，以进行空间生命检测和水质监测。在这里，我们讨论了在悬浮在玻璃芯片上的 20 nm 厚氮化硅膜中制造直径约 1.6 到 20 nm 的氮化硅孔及其性能。我们检测含有单一分析物的纯实验室样品，包括 DNA、BSA、microRNA、TAT 和聚 D-赖氨酸氢溴酸盐。我们还测量了环境（混合分析物）样本，其中包含 NASA Ames 提供的南极污垢。对于 DNA 测量，除了使用 KCl 和 NaCl 溶液外，我们使用了人工（合成）海水，它是模拟天然海水成分的不同盐类的混合物。这些样品中加入了不同浓度的双链 DNA (dsDNA) 片段，以确定候选环境条件下纳米孔灵敏度的极限。纳米孔芯片被清洗并重新用于连续测量。使用独立的 1MHz 带宽 Chimera 放大器来确定人工海水中的 DNA 浓度，我们可以在几分钟的实际时间范围内检测到该浓度。我们还设计并开发了一种新型紧凑型纳米孔阅读器，这是一种带有微型流体单元的便携式读出设备，可以在高达 100 kHz 的带宽下获取易位数据。使用这种新仪器，我们记录了 400 bp、1000 bp、