Yu Chen - University of Strathclyde
Yu Chen - University of Strathclyde
Yu Chen - University of Strathclyde
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Gold Nanoparticles<br />
<strong>Yu</strong> <strong>Chen</strong><br />
Department <strong>of</strong> Physics<br />
<strong>University</strong> <strong>of</strong> <strong>Strathclyde</strong><br />
Science and Innovation Award Review Meeting<br />
<strong>Strathclyde</strong> <strong>University</strong>, 6 th August 2008
Surface Plasmon <strong>of</strong> Nanorods<br />
• Asymmetric Au nanoparticles generate<br />
effective multi-photon absorption induced<br />
luminescence (MAIL) via near-infrared<br />
excitation.<br />
• The particles are highly photostable and<br />
do not blink.<br />
• Suggested a potential as biological labels<br />
in vivo imaging at the single-particle<br />
level.<br />
• Calculated absorption spectrum <strong>of</strong><br />
elongated ellipsoids with varying aspect<br />
ratios R [from S. Link, et al, J. Phys. Chem.<br />
B, 103, 3073 (1999)].<br />
• Value <strong>of</strong> asymmetric nanoparticles (nanorods):<br />
- Tunable wavelength<br />
- Enhancement in the local electromagnetic field<br />
- PL enhancement<br />
- Polarization<br />
• High effective MAIL generated from 15nm<br />
silica-coated Au nanoparticles [from: R. A.<br />
Farrer, et al., Nano Lett., 5, 1139 (2005)].
Seeded growth method
CTAB Stabilized Gold Nanorods<br />
1.2<br />
1<br />
0.8<br />
0.6<br />
0.4<br />
aft 1hr<br />
aft 2hr<br />
aft 3.5hr<br />
aft 3d<br />
aft 14d<br />
0.2<br />
Seeds ~1.7 ± 0.3 nm<br />
0<br />
400 500 600 700 800 900 1000 1100<br />
Length ~ 50 ± 9 nm, Width ~ 14 ±<br />
2 nm<br />
Aspect ratio = 3.6 ± 0.7
Variation <strong>of</strong> Aspect Ratio<br />
1.2<br />
1<br />
0.8<br />
0.6<br />
aft 2hr<br />
aft 5hr<br />
aft 3d<br />
0.4<br />
0.2<br />
0<br />
400 500 600 700 800 900 1000 1100<br />
μl<br />
μl<br />
80 μl seeds -- λ L = 880 nm<br />
20 μl seeds -- λ L = 945 nm
Stability <strong>of</strong> CTAB Stabilized Gold Nanorods
Growth <strong>of</strong> Size-Selected Nanoclusters<br />
Au 8600 Au 11860<br />
Au 5800<br />
Au 15000
Au 8600<br />
S1418 – He 160 sccm<br />
S1416 – He 80 sccm<br />
S1417 – He 40 sccm<br />
Au 11860<br />
S1263 - He 151.1 sccm<br />
S1415 - He 50 sccm<br />
S1264 - He 15 sccm
Growth and Shape Control <strong>of</strong> Size-Selected Nanoclusters<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
Au 8600<br />
Two types <strong>of</strong> gas phase growth<br />
0.5 1.0 1.5 2.0 2.5 3.0<br />
Aspect ratio<br />
2 nm<br />
2 nm<br />
20 nm
Functionalization <strong>of</strong> Gold Nanorods<br />
• The protein ricin is one <strong>of</strong> the most potent protein<br />
toxins<br />
• Ricin is composed <strong>of</strong> two distinct protein chains, A and<br />
B (~30 kDa each), linked by a disulphide bond.<br />
• The B chain binds onto the cell surface mediating<br />
entry.<br />
• The A chain targets and depurinates an adenine base<br />
at the 28s rRNA, resulting in an inhibition <strong>of</strong> protein<br />
biosynthesis and cell death.<br />
• Conjugate gold nanorods with B chain to investigate<br />
intracellular trafficking <strong>of</strong> ricin as well as other toxins in<br />
A-B family.<br />
A. Electrostatic interaction B. In situ dithiocarbamate formation
Collaborations<br />
Pr<strong>of</strong>. Richard Palmer<br />
Nanoscale Physics Research Laboratory<br />
Department <strong>of</strong> Physics<br />
Birmingham <strong>University</strong><br />
Dr. Jun <strong>Yu</strong> and Dr. James Brewer<br />
SIPBS Pump Primary Project 2008<br />
<strong>Strathclyde</strong> Institute <strong>of</strong> Pharmacy and Biomedical Science<br />
<strong>Strathclyde</strong> <strong>University</strong>
Change language