Covalent attaching protein to graphene oxide via diimide-activated amidation

In this paper, graphene oxide nanosheets (GOS) are functionalized by bovine serum albumin (BSA) via diimide-activated amidation under ambient conditions. The obtained GOS-BSA conjugate is highly water-soluble. Results of atomic force microscopy (AFM). Raman spectra and Fourier transform infrared spectroscopy analysis confirm that GOS-BSA conjugate contains both COS and BSA protein. AFM image shows that GOS are fully exfoliated. Results of cyclic volatammograms show that the protein in the GOS-BSA conjugate retains its bioactivity. The present method may also provide a way to synthesize graphene-based composites with other biomolecules. (C) 2010 Elsevier B.V. All rights reserved.