Department of Chemistry , Loughborough University , Loughborough , Leicestershire LE11 3TU , United Kingdom.
School of Chemical and Physical Sciences , Victoria University of Wellington , Wellington 6140 , New Zealand.
Anal Chem. 2019 Feb 19;91(4):2947-2954. doi: 10.1021/acs.analchem.8b05140. Epub 2019 Jan 29.
Resistive pulse sensors (RPSs) provide detailed characterization of materials from the nanoparticle up to large biological cells on a particle-to-particle basis. During the RPS experiment, particles pass through a channel or pore that conducts ions, and the change in the ionic current versus time is monitored. The change in current during each translocation, also known as a "pulse", is dependent on the ratio of the particle and channel dimensions. Here we present a facile and rapid method for producing flow-RPSs that do not require lithographic processes. The additively manufactured sensor has channel dimensions that can be easily controlled. In addition, the fabrication process allows the sensor to be quickly assembled, disassembled, cleaned, and reused. Furthermore, the RPS can be created with a direct interface for fluidic pumps or imaging window for complementary optical microscopy. We present experiments and simulations of the RPS, showing how the pulse shapes are dependent on the channel morphology and how the device can count and size particles across a range of flow rates and ionic strengths. The use of pressure-driven fluid flow through the device allowed a rapid characterization of particles down to concentrations as low as 1 × 10 particles per mL, which equated to one event per second.
电阻脉冲传感器 (RPS) 可提供从纳米颗粒到大型生物细胞的详细材料特性，具有逐颗粒分析的特点。在 RPS 实验中，颗粒通过一个传导离子的通道或孔，监测离子电流随时间的变化。在每次转位过程中（也称为“脉冲”）电流的变化取决于颗粒和通道尺寸的比例。在这里，我们提出了一种简单快速的方法来制作无需光刻工艺的流动 RPS。通过增材制造的传感器具有可轻松控制的通道尺寸。此外，制造过程允许传感器快速组装、拆卸、清洁和重复使用。此外，RPS 可以直接与流体泵接口，或带有互补的光学显微镜成像窗口。我们展示了 RPS 的实验和模拟，表明了脉冲形状如何取决于通道形态，以及该设备如何在一系列流速和离子强度下对颗粒进行计数和大小分类。通过设备内的压力驱动流体流动，可快速对低至 1×10 个颗粒/mL 浓度的颗粒进行快速特性分析，这相当于每秒一个事件。
