DNA-functionalized silicon nitride nanopores for sequence-specific recognition of DNA biosensor.

Shengwei Tan,Chuanrong Hou,Lei Wang,Yanping Li,Jingjing Yu,Rui Jiang,Quanjun Liu

doi:10.1186/s11671-015-0909-0

Abstract

Nanopores have been proven to be novel and versatile single-molecule sensors for individual unlabeled biopolymer detection and characterization. In the present study, a relatively large silicon nitride (Si3N4) nanopore with a diameter of approximately 60 nm was fabricated successfully using a focused Ga ion beam (FIB). We demonstrated a simple ex situ silanization procedure to control the size and functionality of solid-state nanopores. The presented results show that by varying the silanization time, it is possible to adjust the efficiency of probe molecule attachment, thus shrinking the pore to the chosen size, while introducing selective sensing probes. The functionalization of nanopores was verified by analysis of field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and electrical measurements. Based on this study, we envision that the functionalized silicon nitride nanopores with the DNA probe might provide a biosensing platform for the detection and discrimination of a short single-stranded DNA oligomer of unknown sequences in the future.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-015-0909-0) contains supplementary material, which is available to authorized users.

Highlights

Nanopores have been widely evolved in various devices, which cover many different areas from single-molecule stochastic sensing [1,2,3,4] to medical screening and diagnosis [5], so they play an increasingly important role at the forefront of biotechnology and life science
Optimization of silanization times The preparation procedure required precise control of the first activation step which was highly dependent on the chosen probe molecules and on the final diameter needed for the specific application, but was extremely simple and effective, enabling a very fast realization of a selective solid-state nanopore biosensor
The resizing result of silanization treatment was nicely confirmed by electrical measurements performed on a series of nanopore chips functionalized by using different silanization times

Summary

Introduction

Nanopores have been widely evolved in various devices, which cover many different areas from single-molecule stochastic sensing [1,2,3,4] to medical screening and diagnosis [5], so they play an increasingly important role at the forefront of biotechnology and life science Nanoporebased devices, both biological and synthetic, allow us to detect and interrogate single molecules by monitoring the modulation of the pore electrical conductance. There is widespread concern on nanopores as a potential candidate to achieve the ‘$1,000 genome’ goal set by the US National Institutes of Health [7] Based on all these advantages, such sensors have already been successfully employed to analyze nanoparticles [8,9,10] and to study protein folding or unfolding [3,11].

Methods

Results

Conclusion