Lipid bilayer membrane technologies: A review on single-molecule studies of DNA sequencing by using membrane nanopores

Abstract

Nanopores based on α-hemolysin and MspA represent attractive sensing platforms due to easy production and operation with relatively low background noise. Such characteristics make them highly favorable for sequencing nucleic acids. Artificial lipid bilayer membranes, also referred to as black lipid membranes, in conjunction with membrane nanopores, can be applied to both the detection and highly efficient sequencing of DNA on a single-molecule level. However, the inherently weak physical properties of the membrane have impeded progress in these areas. Current issues impeding the ultimate recognition of the artificial lipid bilayer as a viable platform for detection and sequencing of DNA include membrane stability, lifespan, and automation. This review (with 105 references) highlights attempts to improve the attributes of the artificial lipid bilayer membrane starting with an overview on the present state and limitations. The first main section covers lipid bilayer membranes (BLM) in general. The following section reviews the various kinds of lipid bilayer membrane platforms with subsections on polymer membranes, solid-supported membranes, hydrogel-encapsulated membranes, shippable and storable membrane platforms, and droplet interface bilayers. A further section covers engineered biological nanopore sensor applications using BLMs with subsections offering a comparative view of different DNA sequencing methods, a detailed look at DNA Sequencing by synthesis using alpha-hemolysin nanopores, sequencing by synthesis using the MspA nanopore and quadromer map, and on limitations of sequencing based on synthesis technology. We present an outlook at the end that discusses current research trends on single-molecule sequencing to highlight the significance of this technology and its potential in the medical and environmental fields.