Biomedical Engineering Reference
In-Depth Information
Fig. 8.12
Noncovalent DNA functionalization of graphene oxide (GO) and reduced graphene
oxide (RGO) and the assembly of gold nanoparticles on DNA-coated GO/RGO via gold-thiol
bonding (Reproduced from Ref. [
63
] by permission of The Royal Society of Chemistry)
single-stranded DNA could adsorb on the surface of GO via noncovalent
stacking interaction, hydrophobic force, as well as hydrogen bonding, among which
-
stacking with electron-conjugated domains of GO might have the major
contribution. The resulting DNA-GO composites could be converted into DNA-
coated reduced graphene oxide (DNA-RGO) with hydrazine as a reducing agent.
Our research revealed a strong stabilization effect of DNA on RGO, which usually
has a strong tendency to aggregate and form precipitates due to its significantly
increased hydrophobicity. We verified the existence of DNA on GO and RGO by
appending the DNA strand with a thiol group so that gold nanoparticles (nano-
tags) were able to find the adsorbed DNA and attach to it via gold-thiol bonding.
The AFM images we obtained clearly indicated the randomly distributed Au
nanoparticles in a reasonable density on the DNA-coated GO and RGO nanosheets,
in contrast to control experiments where non-thiolated DNA was used to rule out
nonspecific adsorptions. The success of DNA decoration on GO and RGO provided
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