Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, United States of America.
Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON, CA, Canada.
Nanotechnology. 2024 May 20;35(32). doi: 10.1088/1361-6528/ad460b.
An ion detection device that combines a DNA-origami nanopore and a field-effect transistor (FET) was designed and modeled to determine sensitivity of the nanodevice to the local cellular environment. Such devices could be integrated into a live cell, creating an abiotic-biotic interface integrated with semiconductor electronics. A continuum model is used to describe the behavior of ions in an electrolyte solution. The drift-diffusion equations are employed to model the ion distribution, taking into account the electric fields and concentration gradients. This was matched to the results from electric double layer theory to verify applicability of the model to a bio-sensing environment. The FET device combined with the nanopore is shown to have high sensitivity to ion concentration and nanopore geometry, with the electrical double layer behavior governing the device characteristics. A logarithmic relationship was found between ion concentration and a single FET current, generating up to 200 nA of current difference with a small applied bias.
设计并模拟了一种将 DNA 折纸纳米孔与场效应晶体管 (FET) 相结合的离子检测装置，以确定纳米器件对局部细胞环境的灵敏度。此类设备可集成到活细胞中，在半导体电子设备中创建非生物-生物界面。连续体模型用于描述电解质溶液中离子的行为。漂移-扩散方程用于模拟离子分布，同时考虑电场和浓度梯度。将其与双电层理论的结果进行匹配，以验证该模型在生物传感环境中的适用性。结果表明，与纳米孔结合的 FET 器件对离子浓度和纳米孔几何形状具有高灵敏度，双电层行为控制着器件的特性。发现离子浓度与单个 FET 电流之间存在对数关系，在施加小偏压时可产生高达 200 nA 的电流差。
