Control of nanoparticle shape may initially seem like a scientific curiosity, but its goal goes far beyond aesthetic appeal. The shape not only influences the chemical and optical properties of metal nanoparticles, but also their relevance for medical applications. By changing the shape from spherical to branched, one can change the absorption wavelength from visible to near-infrared. These nanoparticles are useful for hyperthermia treatment of cancer cells. Firstly, it is important to synthesize nanoparticles with special shapes in a controlled way. Secondly, these nanoparticles need to be coated with functional groups for the covalent binding of biomolecules (antibodies). An excellent way to functionalize these nanoparticles is by the use of self-assembled monolayers of thiols with general formula: HS-(CH2)n-PEOm-X. HS- binds covalently to gold nanoparticles, -(CH2)n- is a spacer of carbon atoms, -PEOm- is a spacer which allows better water solubility and avoids non-specific adsorption of undesired biomolecules and -X is a functional group for the attachment of biomolecules. This research describes the successful synthesis of functionalized non-spherical nanoparticles which were stable for several months while the not-SAM-coated nanoparticles relaxed to spherical ones after several days. Finally, the applicability of these nanoparticles was studied in preliminary in vitro tests.
Journal: TechConnect Briefs
Volume: 2, Technical Proceedings of the 2007 NSTI Nanotechnology Conference and Trade Show, Volume 2
Published: May 20, 2007
Pages: 329 - 332
Industry sectors: Advanced Materials & Manufacturing | Medical & Biotech
Topics: Biomaterials, Materials Characterization & Imaging