Pore Structures for High-Throughput Nanopore Devices.

Sou Ryuzaki,Masateru Taniguchi,Rintaro Matsuda

doi:10.3390/mi11100893

Abstract

Nanopore devices are expected to advance the next-generation of nanobiodevices because of their strong sensing and analyzing capabilities for single molecules and bioparticles. However, the device throughputs are not sufficiently high. Although analytes pass through a nanopore by electrophoresis, the electric field gradient is localized inside and around a nanopore structure. Thus, analytes located far from a nanopore cannot be driven by electrophoresis. Here, we report nanopore structures for high-throughput sensing, namely, inverted pyramid (IP)-shaped nanopore structures. Silicon-based IP-shaped nanopore structures create a homogeneous electric field gradient within a nanopore device, indicating that most of the analytes can pass through a nanopore by electrophoresis, even though the analytes are suspended far from the nanopore entrance. In addition, the nanostructures can be fabricated only by photolithography. The present study suggests a high potential for inverted pyramid shapes to serve as nanopore devices for high-throughput sensing.

Highlights

One of the most extreme nanofluidics in nanobiotechnology is a channel with the size of a single molecule, because these nanochannels enable us to handle and analyze single molecules
For the nondoped Si-based inverted pyramid (IP)-shaped nanopore structure, the potential drop is localized inside the structure (Figure 3a), the electric field exists between the electrode and the entrance of the IP-shaped nanopore (Figure 3b)
Since the pore resistance increases with decreasing the cross-sectional area of the pore (see Equation (1)), the resistance inside the IP-shaped nanopore depends on z, namely, the Rpore of the structure is described as: h 2 α

Summary

Introduction

One of the most extreme nanofluidics in nanobiotechnology is a channel with the size of a single molecule, because these nanochannels enable us to handle and analyze single molecules. The device throughput is not sufficiently high because the potential drop is localized inside and around a nanopore structure (Figure A1). One of the relevant factors for the localized potential drop is a higher pore resistance (Rpore) compared with access resistances (Racc), which corresponds to the ionic current resistances inside a nanopore and between the electrode and the nanopore, respectively. Properties of nanopore devices are often discussed with a simple equivalent circuit consisting of the Rpore and the Racc in a series (Figure 1b) In this instance, each resistance can be described by. The potential shows a drastic drop inside the membrane and nanopore, resulting in almost flat electric field gradients in the cis and trans chambers, and small gradients in the vicinity of the nanopore entrance and exit (Figure A1). Mcaicproamcaicthainecse20o2f0a, 1c1o, xnFdOuRctPiEnEgRmREeVmIEbWrane (Cm) [15]

A Racc cis

Methods

Electric Field Gradients in Nanopore Devices