Integrating nanopore sensors within microfluidic networks

Abstract

Nanopore sensing relies on the application of a voltage across a nano-scale aperture fabricated in a thin, insulating membrane and monitoring the ionic current modulations produced by the passage of target biomolecules (proteins, DNA). While traditional solid-state nanopore fabrication using electron microscopy is time-consuming and expensive, a new technique called controlled breakdown (CBD) has been discovered which generates nanopores using only strong electric fields in an aqueous environment. Subsequent treatment of a nanopore with similar high electric fields allows for the precise control of its size and noise properties. We recently demonstrated that CBD can be used to fabricate an array of solid-state nanopores within a single membrane, each individually addressable both fluidically and electrically, directly in a microfluidic environment. By confining the electric field using micro-vias, nanopore formation is localized to specific regions of a membrane, electrical noise is reduced, and a symmetric electric field is generated around the nanopore for increased molecular detection efficiency.