Single ion detection using FET based nano-sensors:a combined drift diffusion and Brownian dynamics 3D simulation study

QC Physics;TK Electrical engineering. Electronics Nuclear engineering

Moore, Iain ; Asenov, Asen

University:University of Glasgow

Department:School of Engineering

关键词: device modelling, bio-nanoelectronics,biosensors;   

Others  :  http://theses.gla.ac.uk/5136/1/2014moorephd.pdf

来源: University of Glasgow

【 摘 要 】

There is an ever increasing requirement for rapid sensing mechanisms for a variety of purposes – from blood analysis to gas detection. In order to allow large throughput, these devices must also be available at low cost per unit. One method which meets these criteria is the interfacing of biological and nano-scale semiconductor elements. Using modern CMOS processing, alongside further post processing, such devices can be created for a variety of purposes. However, development of these devices is expensive and in order to investigate possible structures, a simulation system is ideal.This work details the development, testing and utilisation of such a system. By combining two widely understood simulation methods – Brownian dynamics and drift diffusion – a mix of efficiency and accuracy is achieved. The introduction begins with a section detailing background to the field in order to set the work in context. The development and strict testing regime employed is then described. Initial simulations of a bio-nano interface are then presented with detection of ions though alterations in the drain current of a nominal 35 nm FET. This shows that there is a 5 nA/µm increase in drain current when an ion is moved through a 3 nm lipid layer which is suspended 15 nm above the oxide allowing identification of the period of traversal of the lipid layer. The final chapter indicates the successful detection of individual ions traversing a nano-pore in the presence of biologically significant ionic concentrations. The rate of change of drain current in the FET indicates a 4 σ signal during traversal with a background concentration of ions of 1 mM which allows clear identification of this individual event.