Localized Nanopore Fabrication via Controlled Breakdown

Abstract

Nanopore sensors provide a unique platform to detect individual nucleic acids, proteins, and other biomolecules without the need for fluorescent labeling or chemical modifications. Solid-state nanopores offer the potential to integrate nanopore sensing with other technologies such as field-effect transistors (FETs), optics, plasmonics, and microfluidics, thereby attracting attention to the development of commercial instruments for diagnostics and healthcare applications. Stable nanopores with ideal dimensions are particularly critical for nanopore sensors to be integrated into other sensing devices and provide a high signal-to-noise ratio. Nanopore fabrication, although having benefited largely from the development of sophisticated nanofabrication techniques, remains a challenge in terms of cost, time consumption and accessibility. One of the latest developed methods—controlled breakdown (CBD)—has made the nanopore technique broadly accessible, boosting the use of nanopore sensing in both fundamental research and biomedical applications. Many works have been developed to improve the efficiency and robustness of pore formation by CBD. However, nanopores formed by traditional CBD are randomly positioned in the membrane. To expand nanopore sensing to a wider biomedical application, controlling the localization of nanopores formed by CBD is essential. This article reviews the recent strategies to control the location of nanopores formed by CBD. We discuss the fundamental mechanism and the efforts of different approaches to confine the region of nanopore formation.

Dynamics of DNA Through Solid‐state Nanopores Fabricated by Controlled Dielectric Breakdown

“…However, these techniques are costly, and their use remains confined to laboratories equipped with such expensive research equipment and highly‐trained personnel. Therefore, a new method named controlled breakdown has been gaining interest in the nanopore community [33–36] . It is a low‐cost, scalable fabrication of precisely sized solid‐state nanopores [13,37] .…”

“…Therefore, a new method named controlled breakdown has been gaining interest in the nanopore community. [33][34][35][36] It is a low-cost, scalable fabrication of precisely sized solid-state nanopores. [13,37] One could pierce a single nanopore down to 2 nm in size with sub-nm precision directly in an aqueous solution.…”

Controllable Fabrication of Sub-10 nm Graphene Nanopores via Helium Ion Microscopy and DNA Detection

“…Han et al [36] used RIE to fabricate graphene nanopores with pore diameters of 1-50 nm; however, the efficiency and accuracy of the technique still need to be improved [37]. Rollings et al [38] successfully fabricated nanopores in graphene using CBD; however, the random location of the generated nanopores is difficult to characterise, and additional complex methods are needed to assist in localisation [39]. Hall et al [40] first fabricated nanopores in Si 3 N 4 membranes via helium ion microscopy (HIM).…”