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Cell Glow By Phoebe Bray, Lucy Hague, Jvaireya Akbar, Steven Cline and Matt Franklin
Cell Glow
By Phoebe Bray, Lucy Hague, Jvaireya Akbar, Steven Cline and Matt Franklin
Cell Glow
By Phoebe Bray, Lucy Hague, Jvaireya Akbar, Steven Cline and Matt Franklin
Introduction● Nanocell is currently looking into the development of cellglow.
● Cellglow involves the use of quantum dots which are made up of Cadmium Selenide (CdSe)
nanocrystals
Semiconductor
resistant to photo and chemical degradation
excellent choice for use in biomedical imaging
Cadmium Selenide Quantum Dots
2-10 nm diameter
Manufacturing● Quantum dots were discovered by Alexey Ekimov in 1981
● The term “Quantum dot” was coined by Mark Reed
How are Cadmium Selenide Quantum Dots manufactured?
● can be synthesised using precursors and organic surfactants
● mixture is heated at a high temperature
● Temperature is an important factor as it determines the growth of nanorcystals
● the monomer concentration is also under strict control during nanocrystal growth
● Alternative method is High temperature dual injection
TEM of quantum dots and their corresponding colours at the wavelength of emission
Applications - White Light-Emitting Diodes
● Quantum dots have replaced phosphor-based materials in WLEDs
● Quantum dots have unique optical properties that are more useful than the phosphor-based materials
● The emission wavelength of the quantum dots can be tuned by controlling the size of the nanocrystal size of CdSe
● The fluorescence of the WLEDs can then be tuned
● Quantum dots have fewer scattering effects because of their narrow size distribution
Applications - Hybrid Solar Cells
● Colloidal nanocrystals (NC) combine with polymers to make a photoactive layer
● Cadmium selenide is a colloidal semiconductor nanocrystal
● Can be used as an electron acceptor
● Efficient energy conversions● Large scale synthesis is very
expensive ● Some solvents that coat the
CdSe are hazardous, unstable and not environmentally friendly
● One of the earliest commercial applications of quantum dots
● The quantum dots are tagged to nanoscale agents - DNA
● The quantum dots glow when exposed to UV light
● Can target a particular cell - cancer cells ● Useful in surgery - the surgeon can see
the glowing tumour and use it as a guide for more accurate tumour removal
● Allows medical researchers to understand molecular interactions better
Applications -Biological Markers
Future Applications● Medical uses - medical imaging/screening
● Qubit- unit of quantum information
● Quantum Computers- theoretical computation systems that use quantum-mechanical phenomena such as superposition and entanglement.
Advantages and Disadvantages of CdSe Quantum Dots
Advantages:
● They are better than fluorophore dyes - 20 times brighter
● They make solar cells more efficient
● It is easy to alter the wavelength of light emitted in the 400-4000 nm range - different colours
Disadvantages:
● CdSe is highly toxic - needs a stable polymer shell
● The shells can alter the optical properties and it is also hard to control the size of the particles.
● In aqueous and UV conditions degradation increases - mechanism needs to be studied
X-Ray Diffractometers
Diagram of what happens inside the machine (Molecular Expressions, 2013)
XRay Diffractometer(Molecular Expressions, 2013)
Braggs' Law
D-Spacing (interplanar spacing), explained using Braggs' Law (Henry et. al, 2012)
An example results graph (Henry et. al, 2012)
Benefits
•Non-destructive, fast, easy sample prep
•High-accuracy for d-spacing calculations
•Single crystal, poly, and amorphous materials
•Standards are available for thousands of material systems
Sources of Error
•Specimen displacement
•Instrument misalignment
•Peak distortion due to certain wavelengths
Transmission Electron Microscope (TEM)•Transmission electron microscopy (TEM) is a technique in which a beam of electrons is transmitted through an ultra-thin specimen, interacting with the specimen as it passes through.
•TEMs work in the range 1 micron to 1 nanometre.
• It is a electron microscope which produces an image of a cross-sectional slice of a specimen.
•The TEM uses electromagnetic lenses to focus the electrons into a very thin beam. The electron beam then travels through the specimen you want to study.
•TEMs produce high-resolution, two-dimensional images, allowing for a wide range of scientific and industry applications.
•The limitations for TEM are mainly due to cost but also the preparation of cells for TEM requires fixation with chemicals that can introduce artificial damage.
Ultraviolet - Visible Spectrometer• Ultraviolet–visible spectroscopy refers to
the absorption spectroscopy in the ultraviolet-visible spectral region.
• The range is roughly 10 nm to 800 nm due to the inclusion of ultra violet.
• A beam of light from a visible or UV light source is separated into its wavelengths by a prism. Each single wavelength beam is split into two.
• One beam, the sample beam, passes through a cuvette containing a solution of the compound being studied in a transparent solvent.
• The intensities of these light beams are then measured by electronic detectors and compared.
• UV/Vis spectroscopy is used in analytical chemistry for the determination of different analytes, such as transition metal ions.
• UV-Visible spectroscopy works well on liquids and solutions, but if the sample is solid particles in liquid, the sample will scatter the light.
• Also to obtain reliable data, the peak of absorbance needs to be at least three times higher in intensity than the background noise of the instrument.
A diagram of a UV-Visible
Spectrometer
UV-Visible Spectrum of Rose Bengal
References● ANDERSON, H. (2010). Transmission Electron Microscope. [online] Available:
http://www.microscopemaster.com/transmission-electron-microscope.html.● BOTTRILLl, M., and GREEN, M.; Chem. Commun., 2011, 47, 7039 - 7050● DAVIDSON, M. W. (2013) Latest Gallery Additions, Molecular Expressions. [online] Available at:
www.micro.magnet.fsu.edu/primer/java/interference/index.html (Accessed: 8 December 2014).● EFROS, Al. L.; ROSEN, M. (2000). The electronic structure of semiconductor nanocrystals. Annual Review of
Materials Science 30: 475–521.● HENRY, D., EBY, N., GOODGE, J. and MOGK, D. (2012) X-ray reflection in accordance with Bragg’s Law,
Geochemical Instrumentation and Analysis. X-ray reflection in accordance with Bragg’s Law. [online] Available at: http://serc.carleton.edu/research_education/geochemsheets/BraggsLaw.html (Accessed: 7 February 2015).
● ‘Quantum dot’ (2015) Wikipedia. Wikipedia. Available at: http://en.wikipedia.org/wiki/Quantum_dot
(Accessed: 10 February 2015).● MURRAY, C. B, et al. (2000). Synthesis and characterisation of mono disperse nanocrystals and close-
packed nanocrystal assemblies. [online] Annual review of Materials, 30 (1), p545.
● NANN, T. et.al., (2008) Nature Publishing Group, Quantum dots versus organic dyes as fluorescent labels. [online] Available at: http://nathan.instras.com/ResearchProposalDB/doc-168.pdf
● no date). Technologies >> Preparation of Quantum Dots. Available at: http://www.oceannanotech.com/nav.php?qid=5 (Accessed: 10 February 2015).
● HAN, Lili, QIN, Donghuan, et al. (2006). Synthesis of High Quality Zinc-Blende CdSe Nanocrystals and Their Application in Hybrid Solar Cells. [online]. Nanotechnology, 17 (18).
● XU Xianmei, WANG Yilin, GULE Teri, et al. (2013). Synthesis and Optical Properties of Cadmium Selenide Quantum Dots for White Light-Emitting Diode Application, [online]. Materials Research Bulletin, 48 (3), 983-987.
● The Next Big Thing is Really Small, Jack Uldrich with Deb Newberry, p. 81)
Introduction● Nanocell is currently looking into the development of cellglow.
● Cellglow involves the use of quantum dots which are made up of Cadmium Selenide (CdSe)
nanocrystals
Semiconductor
resistant to photo and chemical degradation
excellent choice for use in biomedical imaging
Cadmium Selenide Quantum Dots
2-10 nm diameter
Manufacturing● Quantum dots were discovered by Alexey Ekimov in 1981
● The term “Quantum dot” was coined by Mark Reed
How are Cadmium Selenide Quantum Dots manufactured?
● can be synthesised using precursors and organic surfactants
● mixture is heated at a high temperature
● Temperature is an important factor as it determines the growth of nanorcystals
● the monomer concentration is also under strict control during nanocrystal growth
● Alternative method is High temperature dual injection
TEM of quantum dots and their corresponding colours at the wavelength of emission
Applications - White Light-Emitting Diodes
● Quantum dots have replaced phosphor-based materials in WLEDs
● Quantum dots have unique optical properties that are more useful than the phosphor-based materials
● The emission wavelength of the quantum dots can be tuned by controlling the size of the nanocrystal size of CdSe
● The fluorescence of the WLEDs can then be tuned
● Quantum dots have fewer scattering effects because of their narrow size distribution
Applications - Hybrid Solar Cells
● Colloidal nanocrystals (NC) combine with polymers to make a photoactive layer
● Cadmium selenide is a colloidal semiconductor nanocrystal
● Can be used as an electron acceptor
● Efficient energy conversions● Large scale synthesis is very
expensive ● Some solvents that coat the
CdSe are hazardous, unstable and not environmentally friendly
● One of the earliest commercial applications of quantum dots
● The quantum dots are tagged to nanoscale agents - DNA
● The quantum dots glow when exposed to UV light
● Can target a particular cell - cancer cells ● Useful in surgery - the surgeon can see
the glowing tumour and use it as a guide for more accurate tumour removal
● Allows medical researchers to understand molecular interactions better
Applications -Biological Markers
Future Applications● Medical uses - medical imaging/screening
● Qubit- unit of quantum information
● Quantum Computers- theoretical computation systems that use quantum-mechanical phenomena such as superposition and entanglement.
Advantages and Disadvantages of CdSe Quantum Dots
Advantages:
● They are better than fluorophore dyes - 20 times brighter
● They make solar cells more efficient
● It is easy to alter the wavelength of light emitted in the 400-4000 nm range - different colours
Disadvantages:
● CdSe is highly toxic - needs a stable polymer shell
● The shells can alter the optical properties and it is also hard to control the size of the particles.
● In aqueous and UV conditions degradation increases - mechanism needs to be studied
X-Ray Diffractometers
Diagram of what happens inside the machine (Molecular Expressions, 2013)
XRay Diffractometer(Molecular Expressions, 2013)
Braggs' Law
D-Spacing (interplanar spacing), explained using Braggs' Law (Henry et. al, 2012)
An example results graph (Henry et. al, 2012)
Benefits
•Non-destructive, fast, easy sample prep
•High-accuracy for d-spacing calculations
•Single crystal, poly, and amorphous materials
•Standards are available for thousands of material systems
Sources of Error
•Specimen displacement
•Instrument misalignment
•Peak distortion due to certain wavelengths
Transmission Electron Microscope (TEM)•Transmission electron microscopy (TEM) is a technique in which a beam of electrons is transmitted through an ultra-thin specimen, interacting with the specimen as it passes through.
•TEMs work in the range 1 micron to 1 nanometre.
• It is a electron microscope which produces an image of a cross-sectional slice of a specimen.
•The TEM uses electromagnetic lenses to focus the electrons into a very thin beam. The electron beam then travels through the specimen you want to study.
•TEMs produce high-resolution, two-dimensional images, allowing for a wide range of scientific and industry applications.
•The limitations for TEM are mainly due to cost but also the preparation of cells for TEM requires fixation with chemicals that can introduce artificial damage.
Ultraviolet - Visible Spectrometer• Ultraviolet–visible spectroscopy refers to
the absorption spectroscopy in the ultraviolet-visible spectral region.
• The range is roughly 10 nm to 800 nm due to the inclusion of ultra violet.
• A beam of light from a visible or UV light source is separated into its wavelengths by a prism. Each single wavelength beam is split into two.
• One beam, the sample beam, passes through a cuvette containing a solution of the compound being studied in a transparent solvent.
• The intensities of these light beams are then measured by electronic detectors and compared.
• UV/Vis spectroscopy is used in analytical chemistry for the determination of different analytes, such as transition metal ions.
• UV-Visible spectroscopy works well on liquids and solutions, but if the sample is solid particles in liquid, the sample will scatter the light.
• Also to obtain reliable data, the peak of absorbance needs to be at least three times higher in intensity than the background noise of the instrument.
A diagram of a UV-Visible
Spectrometer
UV-Visible Spectrum of Rose Bengal
References● ANDERSON, H. (2010). Transmission Electron Microscope. [online] Available:
http://www.microscopemaster.com/transmission-electron-microscope.html.● BOTTRILLl, M., and GREEN, M.; Chem. Commun., 2011, 47, 7039 - 7050● DAVIDSON, M. W. (2013) Latest Gallery Additions, Molecular Expressions. [online] Available at:
www.micro.magnet.fsu.edu/primer/java/interference/index.html (Accessed: 8 December 2014).● EFROS, Al. L.; ROSEN, M. (2000). The electronic structure of semiconductor nanocrystals. Annual Review of
Materials Science 30: 475–521.● HENRY, D., EBY, N., GOODGE, J. and MOGK, D. (2012) X-ray reflection in accordance with Bragg’s Law,
Geochemical Instrumentation and Analysis. X-ray reflection in accordance with Bragg’s Law. [online] Available at: http://serc.carleton.edu/research_education/geochemsheets/BraggsLaw.html (Accessed: 7 February 2015).
● ‘Quantum dot’ (2015) Wikipedia. Wikipedia. Available at: http://en.wikipedia.org/wiki/Quantum_dot
(Accessed: 10 February 2015).● MURRAY, C. B, et al. (2000). Synthesis and characterisation of mono disperse nanocrystals and close-
packed nanocrystal assemblies. [online] Annual review of Materials, 30 (1), p545.
● NANN, T. et.al., (2008) Nature Publishing Group, Quantum dots versus organic dyes as fluorescent labels. [online] Available at: http://nathan.instras.com/ResearchProposalDB/doc-168.pdf
● no date). Technologies >> Preparation of Quantum Dots. Available at: http://www.oceannanotech.com/nav.php?qid=5 (Accessed: 10 February 2015).
● HAN, Lili, QIN, Donghuan, et al. (2006). Synthesis of High Quality Zinc-Blende CdSe Nanocrystals and Their Application in Hybrid Solar Cells. [online]. Nanotechnology, 17 (18).
● XU Xianmei, WANG Yilin, GULE Teri, et al. (2013). Synthesis and Optical Properties of Cadmium Selenide Quantum Dots for White Light-Emitting Diode Application, [online]. Materials Research Bulletin, 48 (3), 983-987.
● The Next Big Thing is Really Small, Jack Uldrich with Deb Newberry, p. 81)
