Asadzadeh Homayoun, Renkes Scott, Kim MinJun, Alexandrakis George
University of Texas at Arlington, Bioengineering Department, Arlington, TX 76010, USA.
Southern Methodist University, Department of Mechanical Engineering, Dallas, TX 75275, USA.
Sens Biosensing Res. 2024 Dec;46. doi: 10.1016/j.sbsr.2024.100694. Epub 2024 Sep 21.
A novel method of AC sensing is presented that uses a double nanohole (DNH) nanoaperture atop a solid-state nanopore (ssNP) to trap analytes and measure their optical and electrical properties. In this method analytes are propelled by an external applied voltage towards the sensor until they are trapped at the DNH-ssNP interface via a self-induced back action (SIBA) plasmonic force. We have previously named this method SIBA Actuated Nanopore Electrophoresis (SANE) sensing and have shown its ability to perform concurrent optical and DC electrical measurements. Here, we extend this method to AC sensing of 20 nm SiO (silica) nanoparticles, using voltage modulation over a wide range of frequencies applied on top of a baseline DC bias. The sensor was constructed using two-beam GFIS Focused Ion Beam (FIB) lithography, incorporating Ne FIB to mill the DNH and He FIB to drill a central 30 nm ssNP. We utilized COMSOL Multiphysics simulations to explore the multi-frequency AC current conductance properties of the silica nanoparticles trapped at the SANE sensor. These simulations computed conductance changes and phase shifts induced by the presence of the nanoparticle over an AC frequency range of 20 Hz to 100 kHz. Experimental measurements confirmed the trends seen in the computational data. Additional computational studies were then performed to dissect the underlying mechanisms driving the observed AC measurements. Looking forward, we aim to adapt this technology for probing therapeutic nanoparticles non-invasively, offering a promising tool for enhancing quality control of nanoparticle-mediated drug and gene delivery systems.
本文提出了一种新型交流传感方法，该方法利用固态纳米孔（ssNP）顶部的双纳米孔（DNH）纳米孔径来捕获分析物并测量其光学和电学性质。在这种方法中，分析物在外加电压的作用下被推向传感器，直到它们通过自感应背向作用（SIBA）等离子体力被困在DNH-ssNP界面处。我们之前将这种方法命名为SIBA驱动纳米孔电泳（SANE）传感，并展示了其进行同步光学和直流电学测量的能力。在此，我们将该方法扩展到对20 nm SiO（二氧化硅）纳米颗粒的交流传感，在基线直流偏置之上施加宽频率范围的电压调制。该传感器是使用双束气体聚焦离子束（GFIS）聚焦离子束（FIB）光刻技术构建的，结合氖离子束来铣削DNH，氦离子束来钻出一个30 nm的中心ssNP。我们利用COMSOL Multiphysics模拟来探索被困在SANE传感器处的二氧化硅纳米颗粒的多频交流电流传导特性。这些模拟计算了在20 Hz至100 kHz的交流频率范围内纳米颗粒的存在所引起的电导变化和相移。实验测量证实了计算数据中看到的趋势。然后进行了额外的计算研究，以剖析驱动观察到的交流测量结果的潜在机制。展望未来，我们旨在将这项技术应用于无创探测治疗性纳米颗粒，为加强纳米颗粒介导的药物和基因递送系统的质量控制提供一个有前景的工具。
