Bionanotech: Molecular Plasmonics in medicine and nanobiosensors

EEE-413 (Sec-2)
Presentation on
Molecular Plasmonics for
Biology and Nanomedicine
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Names and ID’s of the Group Members
Names ID’s
Kazi Humayun Kabir 2013-3-80-020
Md. Zahidul Islam 2015-1-80-025
Ridwan Ahmed 2015-1-80-029
Md. Siddikur Rahman 2015-1-80-048
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Outline:
Molecular plasmonics for biology and nanomedicine
• Nanobiotech: Nanomedicine & Nanobiosensors
• Molecular plasmonics
• Localized surface plasmon resonance (LSPR)
 Plasmon–molecule interactions
 Three major applications
(1) Optical Effect
(i) Biosensors based on LSPR modulation
(ii) Surface-enhanced Raman spectroscopy (SERS)
(iii) Plasmonic nanoscopy & imaging
(2) Thermal Effect
(i) Photothermal therapy
(ii) Smart nanocarriers
(3) Mechanical Effect
(i) Plasmonic tweezers
• Future perspective
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Outline:
(1) Optical Effect
(2) Thermal Effect
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Nanomedicine
The vision that Richard Feynman shared in 1959 has now been made
possible. He said it would be interesting in surgery if we could swallow the
surgeon.
Nanomedicine involves cell-by-cell regenerative medicine
Important issues
Biocompatibility: Can these new materials and devices work within the body, or will
they be rejected?
Interfacing: Will the new biomaterials we develop work outside living things—
enabling them to be interfaced with electronics and machines in a way that we can
safely use?
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Nanobiosensors
a biosensor is a measurement system for the detection of an analyte that
combines a biological component with a physicochemical detector and a
nanobiosensor is a biosensor that on the nano-scale size
Optical biosensors
Electrical biosensors
Electrochemical biosensors
Nanotube based biosensors and many more…
Surface plasmon resonance (SPR) biosensor was first demonstrated for
biosensing in 1983 by Liedberg et al.
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Bionanotech: Medicine & Sensor
Bionanotechnology is an emerging branch of biology and nanomedicine
Why do we want medical ‘nano’-particles?
Their size enables them to interact directly with most biomolecules
Requires collaboration of experts from various fields
Molecular Plasmonic is the study of light interacting with nanostructured
materials that can support a surface plasmon resonance excitation
Sensing and treatment of disease using plasmonic effect.
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Outline:
(1) Optical Effect
(2) Thermal Effect
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Molecular Plasmonics
 The interaction between confined
electromagnetic (EM) effects and nearby
molecules has led to the emerging field
known as molecular plasmonics.
Using plasmonics effects we are capable
of
Sensing,
 Spectral analysis,
 Imaging,
Delivery,
 Manipulation and
Heating of molecules, biomolecules or cells
Figure 01: Three types of molecule–plasmon
resonance couplings in molecule–metal
nanoparticle hybrids
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Outline:
(1) Optical Effect
(2) Thermal Effect
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Localized surface plasmon resonance (LSPR)
When an external light wave is incident on a
nanosphere, its electric field periodically
displaces the sphere’s electrons with respect to
the lattice. This results in oscillating electron
density – a localized surface plasmon resonance.
Can be used
In vivo application
In vitro application
Figure 02 : Basic
principles of localized
surface plasmon
resonance
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Outline:
(1) Optical Effect
(2) Thermal Effect
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Plasmon–molecule interactions
• Three types of molecule–
plasmon interactions:
I. Optical,
II. Mechanical and
III. Thermal
Ref: Zheng et al. Molecular plasmonics for biology and nanomedicine
Figure 03: Schematic summarizing and
structuring biological and nanomedical
applications of molecular plasmonics.
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Outline:
(1) Optical Effect
(2) Thermal Effect
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Application using Optical Effect
(i) Nanobiosensors based on LSPR modulation
A wide range (from UV to mid-infrared) of LSPR
wavelengths are obtained with metal
nanoparticles of various shapes and sizes
LSPR peak wavelength, intensity and/or bandwidth
can be modulated by molecular adsorption,
desorption or even conformational changes that
induce variations in the refractive index Figure 04: Localized surface plasmon
resonance range of metal nanoparticles
of different shapes
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Application using Optical Effect (Cont…)
(i) Nanosensors based on LSPR
modulation
detecting molecules, biomolecules
and cellular signaling
A significant milestone for LSPR
nanosensors is to reach the single-
molecule detection limit
One of the major challenges for
LSPR based nanosensors is to
identify unknown molecules
Figure 6. Three types of molecule–plasmon resonance
couplings in molecule–metal nanoparticle hybrids
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Outline:
(1) Optical Effect
(2) Thermal Effect
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(ii) Surface-enhanced Raman
spectroscopy (SERS)
In Raman scattering, photons are scattered
inelastically, either losing energy or gaining
energy equal to the molecular vibrations
of the probed material.
SERS studies molecular structures,
dynamics, and various biological processes
detecting transformational and structural
changes in functional proteins and other
biomolecules
Figure 06: Surface-enhanced Raman spectroscopy.
(A) Schematic sample geometry for nanoparticle-
based SERS. (B) Raman spectrum of p-
mercaptoaniline collected with no nanoshells (blue)
and SERS spectra with nanoshells (red).
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Outline:
(1) Optical Effect
(2) Thermal Effect
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(iii) Plasmonic nanoscopy & imaging-
Optical imaging of nanoscale object exhibits challenges because of the
diffraction limitation of light
Near-field scanning optical microscopy (NSOM), plasmonic nanoscopy is
capable of nanoscale biological and medical imaging with-
 high signal-to-noise ratio,
high spatial and temporal resolution and
 low illumination power
Resolution up to 5 nm
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Examples
Based on plasmon resonance energy transfer spectroscopy, real-time
production of cytochrome c in living HepG2 cells has been imaged.
Zheng et al. successfully applied SERS to study the reversible
photoswitching of isolated azobenzene-functionalized molecules
inserted in self-assembled monolayers .
Estrada and Gratton achieved a high-resolution 3D image of biological
fibers such as collagen and actin filaments by moving a single Au
nanoparticle along the fibers with near-infrared (NIR) femtosecond
pulses and measuring its trajectory
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Outline:
(1) Optical Effect
(2) Thermal Effect
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Application Using Thermal Effect
Plasmon-enhanced photothermal effects in
metal nanoparticles successfully
demonstrated for cancer therapy
laser excitation is used to kill tumor cells
selectively (schema right)
High EM energy density surrounding
nanoparticles is converted into thermal
energy that heats the metal nanoparticles
locally.
the particles are in or near the cancer cells,
and causes the cells to reach a temperature
approximately 15–20°C above physiological
temperature, high enough to induce
apoptosis .
Figure 07: Plasmonic photothermal therapy.
Schematic of Au nanoparticles adsorbed selectively
on tumors
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Outline:
(1) Optical Effect
(2) Thermal Effect
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Application Using Thermal Effect (Cont…)
Metal nanoparticles that use plasmon-
enhanced photothermal effects to release drug
molecules that were conjugated to their
surfaces have shown great promise
Because of their large surface-to-volume ratios,
nanoparticles are ideal carriers of
oligonucleotides such as ssDNA, siRNA and
plasmid DNA
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Examples
Figure 08: Plasmonic gene therapy.
(A) Concept of gene release by
oligonucleotides on plasmonic
carriers with optical switch
activation. (B) Left: tunable metal
nanorod carriers based on different
aspect ratios. Middle: scanning
electron microscopy image of
nanorod with an aspect ratio
(length/diameter) of 3.5. Right:
axisymmetric FEMLAB simulation
demonstrating localized heat
distribution at the nanorod surface
at steady state.
Plasmonic Gene Therapy
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Outline:
(1) Optical Effect
(2) Thermal Effect
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Applications based on mechanical effects
(i) Plasmonic tweezers-
Plasmonic tweezers able to capture, trap stably and
manipulate single-molecules/biomolecules with
nanoscale precision
Transfer photon momentum to a
microparticle/nanoparticle, which experiences two
optical forces –
1. a scattering force and
2. a gradient force
 These two forces allow plasmonic tweezers to operate
at low power with reduced optical inference or damage
to biomolecules and cells
Figure 09: Plasmonic tweezers (A &
B) The optical trapping of 200-nm
beads near the substrate without and
with nanodot pairs, respectively
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Outline:
(1) Optical Effect
(2) Thermal Effect
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Future perspective
• Tremendous opportunities for sensing, imaging, manipulating,
delivering and smoldering biological molecules
• Can potentially integrate sensing, spectral analysis, molecular
manipulation, drug delivery, gene switches and photothermal therapy
onto the same nanoparticle platform.
• Will require strong collaboration between experts in many different
fields such as physics, Nanomedicine engineering, chemistry, biology
and pharmacology
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Bionanotech: Molecular Plasmonics in medicine and nanobiosensors

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