Issue 73, 2016

Dispersal of pristine graphene for biological studies


Contradictions in the reported biocompatibility of graphene-related materials have been attributed to differences in their preparation. Herein, we address the conflicting behavior of different pristine graphene dispersions through their careful preparation and characterization in aqueous media. Although exfoliated in different media, all graphene dispersions were physically similar and comprised few-layer graphene flakes of 100 to 400 nm mean length with relatively defect-free basal planes. The dispersions were colloidally stable, including in physiological saline and when organic solvents were exchanged with water by dialysis, due to their negative zeta potentials (−28 mV to −60 mV) from interaction with water and the different dispersants. Thus, we have been able to establish the influence of pre-association with different dispersants, including those likely to be encountered during the transport and excretion of graphene in vivo. Shear-forced association with neutral phospholipids was transient, as the lipids desorbed to form liposomes, and left a hemolytic dispersion, whereas other dispersions were not hemolytic. High boiling point solvents widely used to exfoliate graphene are toxic and viewed difficult to remove, but were readily removed by simple dialysis. Human serum albumin readily and stably adsorbed in predominantly monomeric form to pristine graphene in physiological saline, which may be expected in vivo. This work shows the large influence that different adsorbates can have on the behaviour of otherwise physically-similar graphene.

Graphical abstract: Dispersal of pristine graphene for biological studies

Supplementary files

Article information

Article type
10 May 2016
17 Jul 2016
First published
18 Jul 2016
This article is Open Access
Creative Commons BY license

RSC Adv., 2016,6, 69551-69559

Author version available

Dispersal of pristine graphene for biological studies

A. P. A. Raju, S. C. Offerman, P. Gorgojo, C. Vallés, E. V. Bichenkova, H. S. Aojula, A. Vijayraghavan, R. J. Young, K. S. Novoselov, I. A. Kinloch and D. J. Clarke, RSC Adv., 2016, 6, 69551 DOI: 10.1039/C6RA12195K

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity