Biomedical Applications of Graphene and Graphene Oxide

Abstract

Graphene has unique mechanical, electronic, and optical properties, which researchers have used to develop novel electronic materials including transparent conductors and ultrafast transistors. Recently, the understanding of various chemical properties of graphene has facilitated its application in high-performance devices that generate and store energy. Graphene is now expanding its territory beyond electronic and chemical applications toward biomedical areas such as precise biosensing through graphene-quenched fluorescence, graphene-enhanced cell differentiation and growth, and graphene-assisted laser desorption/ionization for mass spectrometry. In this Account, we review recent efforts to apply graphene and graphene oxides (GO) to biomedical research and a few different approaches to prepare graphene materials designed for biomedical applications. Because of its excellent aqueous processability, amphiphilicity, surface functionalizability, surface enhanced Raman scattering (SERS), and fluorescence quenching ability, GO chemically exfoliated from oxidized graphite is considered a promising material for biological applications. In addition, the hydrophobicity and flexibility of large-area graphene synthesized by chemical vapor deposition (CVD) allow this material to play an important role in cell growth and differentiation. The lack of acceptable classification standards of graphene derivatives based on chemical and physical properties has hindered the biological application of graphene derivatives. The development of an efficient graphene-based biosensor requires stable biofunctionalization of graphene derivatives under physiological conditions with minimal loss of their unique properties. For the development graphene-based therapeutics, researchers will need to build on the standardization of graphene derivatives and study the biofunctionalization of graphene to clearly understand how cells respond to exposure to graphene derivatives. Although several challenging issues remain, initial promising results in these areas point toward significant potential for graphene derivatives in biomedical research.

Mesoporous carbon biomaterials

“…Of the carbon-family members, sp 2 carbon-based materials such as fullerene [4,5], carbon nanotubes [1,[6][7][8][9][10][11], carbon dots [12][13][14], and graphene [15][16][17][18], have been explored for promising applications in biomedicine, including drug delivery, gene transfection, photothermal therapy, photodynamic therapy, biosensing, and even tissue engineering [19][20][21]. For instance, the hollow space in fullerene/carbon nanotubes and large surface-to-volume ratio of graphene can be used for the encapsulation and intracellular delivery of therapeutic agents.…”

Graphene-Based Nanomaterials in Bioimaging

“…Nitrogen-doped GQDs (N-GQDs) exhibit a strong two-photon absorption cross section as high as 48000 Göppert-Mayer units and are demonstrated as an efficient two-photon fluorescent probe for TPFI (67). More interestingly, graphene and its derivatives also display great potential as efficient quenchers in graphenebased nanosensors for many fluorescent moieties, including small molecule dyes, QDs and conjugated polymers via FL resonance energy transfer or charge transfer (68). Additionally, the intrinsic Raman signals of GOs, G line (the E 2g mode of sp 2 carbon atoms) around 1600 cm −1 and the D line (the symmetry A 1g mode) around 1350 cm −1 , can be further enhanced by metal nanoparticles (Au or Ag) for surface-enhanced Raman scattering (SERS) application in Raman imaging (32).…”

Graphene and graphene oxide as nanomaterials for medicine and biology application

“…Particularly, GO, due to its excellent surface functionability, amphiphilicity, aqueous appearance, fluorescence quenching ability and surface-enhanced Raman's scattering property, is chemically exfoliated from other graphene derivatives [15]. These exceptional characteristics of GO is due to the small sp 2 carbon domains which are enclosed by sp 3 domains and the hydrophilic functional groups containing oxygen due to its distinctive chemical structure [16].…”