Gold-silica nanocoating of DNA origami
Publicerad
Författare
Typ
Examensarbete för masterexamen
Program
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Finding new ways to empirically determine the 3D structure of biomolecules could
greatly increase our knowledge of their function or toxicity. A long-standing issue is
that biomolecules are sensitive and therefore difficult to analyze without disrupting
their structure, and thereby invalidating the measurement. A promising imaging
technique is atom probe tomography, which has high lateral and axial resolution,
while obtaining chemical composition through mass spectrometry, yet the sensitivity
issue of biomolecules remains. This Master’s thesis aims to compose an atom probe
tomography sample fabrication route for biomolecules, by initially stabilizing the 3D
structure with nanoshells. DNA origami was folded to a distinguishable and known
structure to evaluate if the nanoshell coating process affects the structure or if it is
preserved. A modified St¨ober process was used to form a thin silica shell around the
DNA origami. This was done at mild conditions to preserve the native structure,
and followed by a gold coating step, resulting in multi-layered core-shell particles.
Scanning electron microscopy images and transmission electron microscopy images of
the particles revealed features corresponding to the known DNA structure suggesting
successful nanoshell synthesis and 3D structure preservation. What remains before
atom probe tomographic analysis is possible is to form needle shaped samples with
the particles at the apex, and two such paths are presented and explained as future
work. The protocol could then be applied to other biomolecules with unknown
structures to obtain both the chemical composition and the shape.
Beskrivning
Ämne/nyckelord
DNA origami, Nanoshells, Nanoparticles, Atom probe tomography, 3D imaging, Nanobiotechnology