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Transcript 
Introduction of
Nanoplasmonics
2011 Spring Semester
What we are going to deal with
• Metallic Nanoparticle or 2-D Nanostructure
• Metallic Thin Film
and Light!!!
Examples of Metallic
Nanoparticles (Standalone)
Examples of Metallic
Nanostructures (2D)
What if
the size of metallic particle
is down to nanoscale?
Surface Plasmon Resonance, Photothermal Effect
and Strong field enhancement
Surface Plasmon Resonance
Noble metal nano-structure
c
k
Group oscillation
of electron cloud
=
Extinction
Resonance
Frequency

m
x
..
.
F(t)
m x c x kx  F (t )
Displacement
White light
Excitation
Resonance
Frequency
f
Material, Size, and
Shape Dependent
Optical Antenna!!!
Multi wavelength
excitation
W. A. Murray, W. L. Barnes, Adv. Mat. (2007)
Extinction
Selective Re-radiation (i.e. Scattering)

Selective Target releasing
by noble nanoparticles
Surface Plasmon Resonance
in Metallic Thin Film
• http://www.youtube.com/watch?v=pRzlzg
ALvqQ&feature=related
Photothermal Conversion
Direct conversion of
optical energy into heat
Optically driven collective
oscillation of electrons
Collision of electrons with
lattice: Phonon relaxation
• Applications of plasmonic photothermal conversion
Laser-induced size-reduction of metallic nanoparticles
Control of gene regulation or protein expression in cell
Targeted local thermotherapy of cancer
Local drug delivery by optical switch
•
E , T 
Enear
Einc
 10
Plain
Nanosphere
Excitation of molecular
vibrations in ambience
T < 10 K
or
Require local high power/pulsed
lasers
Enear
Einc
~ 300
Nanocrescent
Strong Field Enhancement
Conventional Lens Focusing
Plasmonic Lens Focusing
Highly focused
EM field
High Sensitivity
Spatial Resolution
Lens >> 
Target molecules
Focused
Spot
d ~ *
*:
Wavelength
Intensity (A.U.)
Molecular Fingerprint
/nm
Stained Glass & Roman Cup
Applications of
Nanoplasmonics
From Catalysis
to Biology
Photothermal Conversion
Direct conversion of
optical energy into heat
Optically driven collective
oscillation of electrons
Collision of electrons with
lattice: Phonon relaxation
• Applications of plasmonic photothermal conversion
Laser-induced size-reduction of metallic nanoparticles
Control of gene regulation or protein expression in cell
Targeted local thermotherapy of cancer
Local drug delivery by optical switch
•
E , T 
Enear
Einc
 10
Plain
Nanosphere
Excitation of molecular
vibrations in ambience
T < 10 K
or
Require local high power/pulsed
lasers
Enear
Einc
~ 300
Nanocrescent
Video Clip
for Photothermal Effect
http://www.youtube.com/watch?v
=3J9aUQSK_QE
Photothermal Therapy
Molecular Therapeutics:
*
ONCOS
Example ONCOS
Strong Field Enhancement
Conventional Lens Focusing
Plasmonic Lens Focusing
Highly focused
EM field
High Sensitivity
Spatial Resolution
Lens >> 
Target molecules
Focused
Spot
d ~ *
*:
Wavelength
Intensity (A.U.)
Molecular Fingerprint
/nm
Single Molecule Detection by SERS*
*SERS: Surface-enhanced Raman Scattering
Raman Scattering
SERS
Improving Raman scattering by double field
enhancement
Excitation
Molecule
Raman
Scattering
Adsorbed
Molecule
Raman
Scattering
Raman molecular
fingerprint spectrum
Good: Molecular fingerprint signatures
Label-free detection
Bad: Signal too weak
Metallic
Nanostructure
Raman SignalLocal Field Enhancement4
Enhancement
Last Video Clip for This
Hour
http://www.multimedia.ethz.ch/epis
ode_play/?doi=10.3930/ETHZ/AV9b0a8bfb-a42e-49c1-8237bbd643ddc7a8
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