Colloidally-stable inorganic nanocrystals have a wide range of envisaged
applications in biological environments. To reach their potential, the nanocrystals
need to be stable in aqueous environments and have pendant functionality
available for attachment of biomolecules. In this thesis, new methods for the
transfer of nanocrystals from organic to aqueous media are developed and the
interaction of aqueous stabilised particles with serum proteins is investigated.
In Chapter 3, a new method for the synthesis of a thin silica layer upon the
surface of nanocrystals is demonstrated. The method uses the hydrophobic interaction
between an amphiphilic polymer and nanocrystal ligands to provide
a foundation for growth of a silica layer. The coated nanocrystals are characterised
using a wide range of techniques confirming that the presence and
location of the silica shell.
In Chapter 4, custom-synthesised amphiphilic polymers for water transfer
and functionalisation of nanocrystals are synthesised, characterised and tested.
Commercially-available polymers used for this purpose are examined, leading
to a rationale for custom-design. Partial water transfers were achieved using
activated ester copolymers with styrene but no transfers were achieved the
octadecylacrylate copolymers. Poly(ethylene glycol) containing monomers
were also used but yielded no transfers. This suggests that behaviour of the
polymer during the coating procedure is intimately linked to the structure of
the polymer.
In Chapter 5, small-angle neutron scattering is used to elucidate structural
information for the protein corona formed on nanocrystals and silica nanoparticles.
Information on the packing of ligands on colloidal nanocrystals
without a amphiphilic polymer coating was determined. The fitting of the
protein corona upon silica nanoparticles was explored using core-shell form
factors but was hampered by complexities within the scattering profiles which
were not accounted for using simple form factors
