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LBT - Lebensmittel und Biotechnologie • Thema anzeigen - Lecture 1 [Einheit 1] Summary [Zusammenfassung]
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 Betreff des Beitrags: Lecture 1 [Einheit 1] Summary [Zusammenfassung]
 Beitrag Verfasst: 26.02.2020, 15:36 
Hefenzüchter/in
Hefenzüchter/in

Registriert: 11.11.2012, 12:46
Beiträge: 291
Nun noch Lecture 1 ... somit sind 3 Teile fertig. Das ist nur die Zusammenfassung der
Folien, zum Teil ein wenig ergänzt. Ich fand es zum Lernen einfacher nur den Text
zu haben; die Bilder sind nett aber nicht unbedingt gut zu gebrauchen für die
Prüfung. Die Prüfungsfragen scheinen aber doch über die Folien hinauszugehen.

Zur Formatierung: ich habe das auf ~80 Zeichen pro Zeile begrenzt im Editor,
da dies einfacher war. Wer das schöner möchte kann es ja dann einfach
copy/pasten in ein Liberoffice/Microsoft Office Dokument.

Lecture 1: Introductory course

This course should...

1) give you an overview of nano science and nanotechnology in relation
to biological sciences and biotechnology
2) help you choose what further knowledge from the physics and
material sciences that would aid your future career
3) introduce you to the kind of research represented by the
Department of Nanobiotechnology (DNBT) at the BOKU

• Nano sciences and technology is 1 of 8 areas of competence
(Kompetenzfelder) of the BOKU.

DNBT overview:

3 Institutes organized around the thematic areas of the department

a) Biologically inspired materials
Univ.-Prof. Erik Reimhult
ao. Prof. Christina Schäffer

b) Biophysics
Univ.-Prof. José Luis Toca-Herrera
ao. Prof. Dietmar Pum

c) Synthetic bioarchitectures
Univ.-Prof. Eva-Kathrin Ehmoser
ao. Prof. Bernhard Schuster

What to learn

Course material:
The slides - defines the course material. Download final slides one
day after each lecture.
Lectures - experience shows that attendance at the lectures improves
exam score

Exam:

Written - the questions will test your understanding of the content.
Learning slides by heart might be sufficient to make you pass, but
not to score well.

Today's objectives:
• Take it easy...
• get through some buzzwords,
• get a feel for what "Nano science" could be,
• get a feel for what Nanomaterials can do,
• ...and why we should care about the nanoscale when we
work with biotechnology.


Nanobio science
• Nano is NOT a specific size.
• Nano is when things are so small that you cannot ignore how small
they are.
• Nano is when the surface begins to dominate.
• Nano is a "new" paradigm and way of thinking.
• Bio is the inspiration.
• Bio/medicine is often the target.


• Biology uses building blocks on the nanoscale and excels
in structure and complexity.

• Physics and chemistry on the nanoscale has more functional
diversity and robustness than biological systems.

What has nano got to do with bio?

→ Biology has building blocks on the nanoscale and work on
the macromolecular and nanoscale
→ Biology does NOT use its building blocks like human engineers

Biological building blocks "on their own":
• build
• respond
• change
• move
• exchange
• rebuild

→ Biology is fluid on the nanoscale!

Molecular self-assembly instead of nuts and bolts:

A new paradigm for engineers:

Human engineers: place things where they want them and bolt them down

whereas

Nature's "biological engineers": not needed! The things know where
to place themselves.

Molecular self-assembly instead of nuts and bolts:

Self-assembly and self-organization on the molecular and nanoscale is
however neither
• magic, nor
• Lego building blocks.

It is (mostly) thermodynamics. Minimizing energy by letting thermally
mobile molecules organize. It is conceptually simple but practically
hard to master thermodynamics (energetics). We also often must
consider kinetics to understand what we observe.

What has physics got to do with "it"?

Physics is obsessed with finding the rules and the models and in
that way goes deeper than the other sciences.

In doing so it, it tends to be both simple and abstract.

NB. Just because you know the rules does not mean that you can play
the game!

Bionanotechnology/science is an interdisciplinary field:
We need people from all fields and backgrounds.

Definition of Nanosciences

Our definition:

Studying physical effects and phenomena in materials and structures
on the mesoscopic size scale where they change dramatically with
size. This is typically thought of as <100nm but is still larger
than single molecules.

Physics reason: length scale where quantum effects are still
observed.

Biology reason: length scale of biological functional units and
vastly increased bioavailability.

Images of viruses: the only real nanobots

Chemistry reason: scale of macromolecules and self- assembly

Disclaimer: No definition can perfectly capture something in
the real world. Thus, also a useful definition of what
nanoscience is has to be vague.

Nanometer the Dimension:

Having a feeling for length scales is important!

...but "nano" as a prefix meaning "very small" can be applied
to other observables than length, e.g., time, energy, etc.

Reasons for making things smaller

• Standard reasons to make things smaller:
• Consuming less material
• Consuming less energy
• Making things faster
• Functional density and multifunctionality
• Scaling laws show you these advantages

Nano science is interface (surface) science

This means that "nNano-properties" often result from a large
surface-to-volume ratio. Interactions of surface atoms and
molecules with other objects and fields are much stronger
than interactions of atoms and molecules in the bulk material
due to the asymmetry of their environment and their proximity.

The Origin of Nano(bio):

• In 1757 Benjamin Franklin calmed the waves on the sea after his ship
to England with some drops of oil and repeated the experiment by
covering all of Clapham pond (1 acre) by spreading a measure of
olive oil (oleic acid) when he arrived in England.
• Lord Rayleigh calculated in 1890 for the same experiment that the
layer had to be only 1.6 nm thick and still could completely
change the pond's surface properties.
• A similar technique was used by Gorter to calculate that the
cell membrane is a layer of 2 molecules each 2-3 nm thick.

What is Nanotechnology:

• Nanotechnology is NOT the microtechnology made smaller.
• The physics changes at the nanoscale; thus, the engineering also
changes.

Commonly heard definitions:

• Manufacturing of materials and structures of which at least
one dimension is <100nm.
• To manipulate atoms and molecules on their own length scale
(the nanoscale).

New properties:

→ Lit from outside
→ Lit from inside
...that you do not always see at first glance.

The Lycurgus cup:

Effect resulting from plasmon light scattering by 70 nm gold and
silver colloids in the glass created by mixing in minute amounts
of noble metals during manufacturing of large quantities of
glass. It makes the cup change color and feel alive.

New properties ... but in use since ancient times.
Damascus saber:

Arabs and Japanese used nanomaterials to strengthen their
weapons. (Cementite nanowires encapsulating carbon nanotubes)

Milestones in (bio)nanotechnology

400 a.D.: Demokritos philosophizes about the undivisable smallest unit the "Atom"
1857: Michael Faraday discovers gold nanoparticles, demonstrating that nanostructured gold produces different-
colored solutions
1931: Max Knoll and Ernst Ruska develops the Electron microscope to visualize the nanoworld
1959: Richard Feynman gives the first vision of nano science and technology
1974: Norio Taniguchi uses for the first time the word "Nanotechnology"
1981: Gerd Binnig and Heinrich Rohrer demonstrate the scanning tunneling microscope (STM)
1985: Harold Kroto and Richard Smalley discover the fullerene (C 60 ), more commonly known as the buckyball
1986: Gerd Binnig, Calvin Quate, and Christoph Gerber demonstrate the atomic force microscope (AFM)
1989: Donald M. Eigler writes "IBM" with single atoms as pixels
1991: Sumio Iijima discovers the carbon nanotube (CNT)
1993: Moungi Bawendi invents a method for controlled synthesis of nanocrystals (quantum dots)
1999: Wilson Ho assembles a molecule from atoms and watches its bonds rotate by STM
2003: Naomi Halas develops gold nanoshells for integrated diagnosis and treatment of breast cancer
2005: Erik Winfree and Paul Rothemund develop theories for DNA-based computation and algorithmic self-
assembly in which computations are embedded in the process of nanocrystal growth
2007: Angela Belcher at MIT builds a battery using a virus
2014: BOKU gets a fluorescence microscope with nanoscale resolution
2019: BOKU gets its first "nano-spin off" company making light-emitting nanocomposites
...modern (bio)nanotechnology is exploding in so many
directions that the last points are truly random.

Origins of pre-modern Nanotechnology:

In 1959 the Physics Nobel laureate Prof. Richard Feynman from Caltech held
a famous talk that opened the eyes of researchers to the possibility of
extending existing known physical laws to create entirely new technology.

In his own words:

"I am not inventing anti-gravity, which is possible someday only if
the laws are not what we think. I am telling you what could be done
if the laws are what we think; we are not doing it simply because
we haven't yet gotten around to it."

The talk was entitled: "There is plenty of room at the bottom".

Feynman offered two prizes:

1. "$1,000 to the first guy who can take the information on
the page of a book and put it on an area 1/25,000 smaller
in linear scale"
2. "$1,000 to the first guy who makes a rotating electric
motor which can be controlled from the outside and
only 1/64 inch cube"

Both prices were claimed without significant new
advancements bummer.

Feynman's influence: Eric Drexler

Feynman's influence on the origins of Nanotechnology was
in practice very limited (nothing happened for 25 years).

Eric Drexler and others picked up his visions in the
90s and imagined nanoscale robots that would
revolutionize medicine and the economy.

This Newtonian (classical mechanics) extention of
the original ideas ignore fundamental physical
restrictions and are therefore science fiction.

A more statistical and fluid version of nanotechnology:

Inspiration from biology rather than robot science.

More applications in medicine and (soft) materials science
than in computer science.

This is where we are headed!

Moore's law:

Moore's law is often quoted to explain why miniaturization
is so important and has impacted our society immensely.
...from these humble beginning:

End of Moore's law:

• Advanced EUV technologies has supported silicon technology down
to below 30 nm. E-beam is now down at 10 nm. Molecular
nanotechnology might stop producing results at 10 nm.
What is then the attractiveness of investing a lot of
money in a completely new technology like molecular electronics?

• Biomaterials offer new opportunities that go beyond the
replacement of existing technologies. For computer chips,
e.g., the lesson to build non-planar structures in 3D (now
also already done by traditional semiconductor technology).

Reconfigurable circuits? Yes, on the nanoscale this would
be hardware possible.

Approaches to structure materials on the nanoscale:

1) The "Top-Down" - Strategy (Solid state materials)
2) The "Bottom-Up" - Strategy (Nanoscale building blocks)

Do note that both strategies share a common goal, which is
"to build the smallest possible functional unit". These
can then be used in meso and macroscopic structures.

Top-Down is usually implemented via Lithography.

Bottom-Up essentially is self-organization of matter, e. g.
as can be seen in biology.

Interestingly enough, we can use DNA for 2D to 3D
self-assembly. The 3D structure is encoded in how
different DNA sequences match. A basic structure would
be a junction (J1), where four different DNA structures
all come together at one place. This is the basis of
"nanoscale assembly".

DNA is simple enough that computational software has been
used to create "DNA origami" that self-assemble complex 3D
shapes. Furthermore evolutionary algorithms have been used
for the structure selection.

Self-assembling protein structures:

S-layers are crystalline, monomolecular (glyco)protein arrays
representing one of the most commonly observed surface
structures in eubacteria and archaea. (The official slides
showed a TEM of freeze etched preparations of bacterial
cells with an S-layer showing square (left) and hexagonal
(right) lattice symmetry.)

Do note that we can also synthesize artificial S-layers.
This can happen by recombinant production of the S-layer.

Biomolecular (nanoscale) building blocks can be used to
coat and structure synthetic functional objects by the
same principles.

What is nanotechnology good for? When do we need it?:

Small is often good:
• Fast
• Strong
• Energy efficient
• Biocompatible
• Can circulate in the body
• Chemically reactive (high surface area)
• ...and even unique properties

Applications:
• Computer processors and memories
• TV screens and displays
• Medicines, food, nutrients and pesticides
• Light and strong materials for transportation
vehicles, wind mills and sports equipment
• Catalysts
• Green chemistry
• Anti-microbials
• Sun-screen
• Biomedical imaging contrast agents
• Paints
• Cosmetics
• Batteries
• Drug delivery
• Body armor
• Self-cleaning surfaces
• Pollution detection and purification
• Solar cells and batteries

We can even have a flexible nano-structured solar cell.

Nanotechnology is economically important; we can see
an (exponentially?) growing economic impact.

But: as with all new technologies nano has had a lot of hype

→ Wild projections for the economic value
→ Wild guesses for what it is actually going to be used for:

• Computers / electronics
• Medicine
• Functional and high-performance materials
• Food / biotechnology
• Cleantech

A large fraction of the public perceives "nano" as dangerous
and negative.

→ many users of nanotechnology in the food and health
sectors are not disclosing it
→ many products labeled "nano" existed before "nanotechnology",
e. g., in food technology

Technological evolution and innovation:

However, will nanotechnology influence society in the way
computers did ... or is it more like electricity, the wheel
or the internet?

That is, is it a product revolution in itself or a much
greater revolution that enables other technologies,
innovations and products, and changes our society.

What properties appear on the nanoscale?:

Optical properties, Conductivity, Magnetism and so forth.

Bucky balls and carbon nanotubes are also important,
such as the Fullerenes or Graphit. The stiffness of
carbon nanotubes is much higher than that of steel.

The carbon future may be graphene, which is a single
layer of carbon (a planar diamond). Graphene is present
in penciles, in stacked sheets as graphite.

Advantages of graphene:

• Extremely high electron mobility
• Highest known conductivity at room temperature
• Highest breaking and tensile strength of any known material
• High optical opacity

Cloaking devices - gold nanoshells:

→ Invisibility cloak

These may have:

• a unique optical properties (plasmons)
• absorb and reemit (scatter) light in new direction
• can assume different colors dependent on size and the
environment (sensor)
• heat up on exposure of strong light (hyperthermia)

Antireflective coatings - moth's eye photonic structures

The real thing: the anti-reflective coatings of a moth's
and a fly's eye. Conserved for more than 50 Mio years.

This has inspired nanotechnology, to create a nanofabricated
anti-reflection coating using the same principle - and to
"diffract light".

Unbleachable colors like in nature – insect photonic crystals

An example is: the Morphos butterfly.

Here, ordered assemblies of nanoparticles and nanopillars
give beautiful colors and are also the way to realize optical
computers working at the speed of light...but insects did
it first, again.

Adhesion everywhere - gecko feet:

Gecko feet are an example for van der Waals forces at work!

The hierarchical structure of gecko feet down to a brush
structure of split 30 nm fibers allows gecko feet to
self-clean and carry the gecko weight, while hanging
upside down from the ceiling.

This has inspired carbon nanotubes, as artificial gecko
feet.

(See also this youtube video:
https://www.youtube.com/watch?v=7ySPl_WVgvc )

Self-cleaning surfaces – The Lotus effect:

Micro- and nanostructured, self-cleaning surfaces according
to nature's model:

Dirt is carried off by rainwater.

Nelumbo nucifera, the sacred Lotus flower.

A droplet takes up the particles loosely covering the leaf
while rolling off, thus cleaning the surface.

Molecular motors:
• Cells make use of several different sets of molecular motors
• Molecular motors, in turn, make use of chemical energy
in order to create motion.

Linear molecular motors ("walkers"):

Dynein moving on microtubule:
• Intracellular material transport typically makes use of
proteins.
• Performing Brownian ratchet type movement along protein
fibers.

Molecular motors are driven Brownian ratchets:

Do not let the "Star Wars AT-ST Walker" fool you! On the
nanoscale movement is always influenced by the random
movement from collisions with water molecules.

Rotary motors:

An example for this is the "F1-ATPase rotating molecular
motor".

• Hydrolysis of ATP to ADP yields the energy to transport
a protein conformation, changing proton at each of the
three alpha-beta subdomains in sequence.

• This results in a quasi rotating movement of the
gamma domain in the center of the F1-ATPase.

A more advanced version powers single-cell organism
propulsion by flagella (from bacteria).

Rotary motors:

The F1-ATPase motor is driven in reverse in complex with
another motor protein, yielding the FoF1-ATP complex, to
synthesize ATP instead.

Membrane pores in nanotechnology:

Membrane proteins in lipid membranes have been applied to
direct electric DNA sequencing. This is today already a
standard technology to read DNA sequences using synthetic
nanopores.

Artificial (poly)ion nanochannels:

Make a nanopore in a thin membrane and measure the pass
through conductance per base pairs.

Use the fluidity of a lipid membrane to measure specifically
recognized proteins diffusing through the nanopore attached
to the lipid membrane.

Nanobiotechnology is used in every step of sensing.

• Single 100-nm liposomes
• Nanoplasmonic sensor element
• Sensor element size selective due to 100-nm topography
• Created by nanoscale self-assembly
• Molecularly functionalized by self-assembly

Observing what you cannot see:

• The modern nanoscience and nanotechnology revolution started
with imaging techniques in the 80s which allowed visualization
of the nano world.
• Nano science is constantly developing with and demanding
development of new characterization methods in:

→ Microscopy
→ Spectroscopy
→ Chemical characterization
→ Physical and chemical interactions
→ Modeling

Light microscopy: (Resolution → 200nm)
Electron microscopy: (Resolution → 0,2nm)
Scanning probe microscopy: (Resolution → <0,1nm)

Summary

• Designing materials on the nanoscale allows the creation of
materials with new properties.
• "Nano" is a size, but cannot be reduced to an easily defined
length scale.
• "Nano" is rather a new paradigm of scientific and technological
thinking bridging several of the traditional scientific
disciplines.
• It is no longer a question of "if" or "when" nanotechnology
will change our lives and society, but rather "how", "how much"
and "what when".

Next lecture:

We start with trying to understand why "small things" might behave
differently compared to "large everyday things", by studying how
properties change as size changes - the so called "scaling theory".


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