Graphene Oxide and Nucleic Acids

Abstract

In recent years, graphene and its oxidized form, graphene oxide (GO), have emerged as a versatile material for various biomedical applications such as biosensing through graphene-quenched fluorescence, nucleic acid adsorption, gene/drug delivery, and photothermal therapeutics. These applications of GO are attributed to properties such as large surface area, excellent aqueous dispersibility, biocompatibility, acceptor of fluorescence resonance energy transfer (FRET) to quench dye fluorescence, and facile modification with functional groups. Importantly, GO exhibits preferential adsorption of single-stranded nucleic acid through π–π stacking interaction and hydrogen bonding between nucleobases and GO surfaces, whereas dsDNA adsorbs on GO with low affinity due to its stiffness and low diffusivity. Several biosensors for detection of a wide range of biomolecules have been developed utilizing GO as fluorescently labeled probes are almost completely quenched upon adsorption on GO’s surface. In the presence of complementary DNA, ds DNA is formed, and fluorescent probe is desorbed from the GO, resulting in florescence restoration which forms the basis for GO-based biosensor platforms. Understanding the fundamental mechanism of interaction between nucleic acid and the GO surface is important for the development of GO-based FRET sensors, gene/drug delivery systems, and biotherapeutics. This chapter provides theoretical considerations of DNA adsorption/desorption and fluorescence quenching of fluorescently labeled DNA by GO. It also summarizes the latest developments in the field of GO and functionalized GO with main applications in vitro and in vivo, including nucleic acid amplification, fluorescent nucleic acid biosensors, gene/drug delivery, and photothermal therapeutics.KeywordsGraphene oxideDNA adsorption and desorptionFluorescence resonance energy transfer (FRET)Fluorescence quenchingNucleic acid amplificationBiosensorNucleic acid aptamerGene deliveryPhotothermal therapeutics