電阻脈衝感應之隨機程序模型

Abstract

奈米孔道在生物科技上的應用非常廣泛，由於其特殊的電動力學現象，使得奈米粒子、分子或者DNA鹼基對在接近奈米孔道時的電泳行為相當複雜。阻抗脈衝的技術便是奈米孔道的相關應用，目前已廣泛被用於測定粒子的大小、形狀、表面電位等等，以往有許多文章從脈衝訊號的大小與形狀來判斷粒子的各項性質，而本研究從隨機程序的模型切入，透過觀察粒子通過奈米孔道時產生訊號的頻率與間隔，估計其通過奈米孔道中不同位置時之電泳速度。粒子受外加電場驅動後具有電泳速度，在裝置中的各個位置之速度不盡相同，透過卜瓦松過程來描述特定位置截面通過的粒子數量，藉以觀察粒子在不同區域時的速度。但由於粒子在特定位置的數量將影響卜瓦松過程的參數，且此裝置為一多階層卜瓦松過程，其對於時間之機率分配難以描述。本研究利用特殊之運算方式，計算各個位置粒子數量之期望值，進而了解粒子在不同位置速度之關係，藉以觀察粒子之各項性質。

Nanopore research has a various application in biotechnology. Electrophoresis of nanoparticles, molecules, or DNA base pairs around nanopore is rather complicated due to particular electrodynamics. Nanopore resistive pulse sensing has been used to characterize the size, shape or zeta potential of nanoparticles. Much research has been conducted to determine the property of a particle through the shape and size of a pulse. In this study, we use the frequency and interval of pulses to build a stochastic process to estimate the electrophoresis of particles. However, the procedure of nanopore resistive pulse sensing is a multi-step poisson process which includes event-dependent parameter, it is hard to get the probability distribution under such circumstance. We use a special method to calculate the expected value of numbers of particles and therefore to estimate the properties of particles.