Anodic current vs' time for an ITO electrode in 0'3 M phosphate buffer 0'05 M EDTA following adsorpt

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Anodic current vs. time for an ITO electrode in
0.3 M phosphate buffer/ 0.05 M EDTA following
adsorption of 10 nm diameter gold particles to
the electrode via DNA hybridization. The
potential was held at 0.3 V vs. Ag/AgCl.
ssDNA/gold nanoparticle conjugates were
hybridized from a 1 pM solution. Arrow indicates
light on. (bottom curve) Photocurrent vs.
ssDNA-modified gold nanoparticle conjugate
concentration. The circle indicates the
photocurrent response in the absence of gold
nanoparticles.
http//www.ncsu.edu/chemistry/dlf/biomolecdetectio
n.pdf (UNC Feldheim group)
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Synthesis of composite polymer nanoparticles and
hollow polymer nanocapsules for bioencapsulation
and intracellular delivery (Feldheim group, UNC)
A metal particle serves as a template for the
formation of thin skins of polymer. Dissolution
of the particle following polymer formation
results in a hollow capsule. Small molecules or
larger biomolecules (horseradish peroxidase,
avidin, DNA) may be trapped in the hollow core
simply by attaching the molecule of interest to
the particle prior to polymer formation. Enymes
maintain their activity inside the hollow polymer
capsules and are even protected to a certain
extent by denaturing agents such as organic
solvents.
A hollow polypyrrole capsule templated with a 200
nm diameter gold particle.
http//www.ncsu.edu/chemistry/dlf/polymernano.html
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(No Transcript)
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Large 2-dimensional metal plates synthesized with
the aid of biomolecules (Lina Gugliotta).
http//www.ncsu.edu/chemistry/dlf/biomaterialsynth
esis.pdf
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Electron micrographs of adenovirus (left) and
gold nanoparticles (right)
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The most effective nuclear targeting in biology
is accompanied by viruses. HepG2 cells incubated
in cell growth medium containing peptide-gold
nanoparticle complexes. The solution in (a)
contained nanoparticles carrying the nuclear
localization peptide sequence (NLS) from the
adenovirus. Nanoparticles were not found inside
the cell because the NLS peptide alone cannot
cross the outer cell membrane. Solution (b)
contained nanoparticles carrying the receptor
mediated endocytosis peptide (RME) from the
adenovirus. These particles pass
through the outer cell membrane but cannot enter
the nucleus because they do not possess a NLS
peptide key. In (c) particles were assembled
which contained both peptide signals linked
together as one long polypeptide (NLS-RME).
These particles were able to cross both the outer
cell membrane and nuclear membrane, but not
nearly as efficiently as particles carrying the
NLS and RME peptides as separate pieces (d).
http//www.ncsu.edu/chemistry/dlf/biomaterialsynth
esis.pdf
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Optical and Electronic Properties of Metal
Nanoparticle Arrays
The Feldheim group has developed methods for
assembling metal particles into arrays of dimers,
trimers and tetramers with psuedo-D       h,
D3h, and Td symmetries. Our assembly strategy has
been to synthesize rigid thiol-functionalized
phenylacetylenes for use as molecular bridges
(see below).
Mixing the thiol-terminated ligand with solutions
of gold or silver nanoparticles results in
nanoparticle arrays with symmetries and
separation distances dictated by the bridging
ligand. For example, the ligand shown above left
results in gold
or silver dimers (below left) while the ligand
above right yields tetrahedral nanoparticle
structures (below right).
http//www.ncsu.edu/chemistry/dlf/opticalprop.html