Self Assembly in Self Assembly in NanotechnologyNanotechnology

Self AssemblySelf Assembly

Self AssemblySelf Assembly is defined as the is defined as the spontaneous association of spontaneous association of numerous individual units of numerous individual units of material into well organized, well material into well organized, well defined structures without external defined structures without external instruction.instruction.

The Proposition of Bottom The Proposition of Bottom Up Manufacturing Up Manufacturing

In 1959 Richard Feynman in an In 1959 Richard Feynman in an address of the American Physical address of the American Physical Society proposed that there was Society proposed that there was plenty of room at the bottom. It was plenty of room at the bottom. It was possible to use very small objects to possible to use very small objects to create large objects. create large objects.

This was the beginning of the idea This was the beginning of the idea for nanotechnology and self for nanotechnology and self assembly.assembly.

Size of NanotechnologySize of Nanotechnology

Nanotechnology involves very Nanotechnology involves very small objects.small objects. Objects less than one-billionth of a meter.Objects less than one-billionth of a meter.

The size of a marble compared to the The size of a marble compared to the earth.earth.

Building materials for nanotechnology are Building materials for nanotechnology are at the molecular level.at the molecular level.

www. www. nisenet.org/publicbeta/articles/think_small/index.htmlnisenet.org/publicbeta/articles/think_small/index.html

Self Assembly is the Key to Self Assembly is the Key to Inexpensive Nano-Inexpensive Nano-

Fabrication Fabrication Molecular self assembly has advantages Molecular self assembly has advantages It is low in cost.It is low in cost.

Reduced fuel costs. Reduced fuel costs. Depend on chemical and physical forces to combine Depend on chemical and physical forces to combine

materials not petroleum.materials not petroleum. Can have high reproducibility. Can have high reproducibility.

In nature, materials self assemble with little In nature, materials self assemble with little variation.variation.

Is able to use a variety of materials for Is able to use a variety of materials for creation. creation. All the building blocks of biology and chemistry.All the building blocks of biology and chemistry.

Building at the Building at the NanoscaleNanoscale

Involves a knowledge of many Involves a knowledge of many disciplinesdisciplines ChemistryChemistry BiologyBiology PhysicsPhysics ElectronicsElectronics MathematicsMathematics

Fundamental Knowledge Fundamental Knowledge May Need to be ModifiedMay Need to be Modified

Understanding how the properties of Understanding how the properties of atoms and molecules will vary at atoms and molecules will vary at such a small scale.such a small scale. Randomization may play a big role.Randomization may play a big role. Atomic properties may vary at such a Atomic properties may vary at such a

small scale.small scale.

Biology Uses Nanoscale Biology Uses Nanoscale Molecules Molecules

Self assembly takes place every day inside Self assembly takes place every day inside your bodyyour body Molecules self organize to form structurally

defined and stable arrangements. Cell membranes Proteins

Enzymes Cell organelles

To view self assembly in a cell go to: http://multimedia.mcb.harvard.edu/media.html and view the Inner Life video

Chemical bonds define Chemical bonds define physical structurephysical structure

The angle of the bonds formed The angle of the bonds formed between the atoms will define the between the atoms will define the structure of the substance formed.structure of the substance formed. Tetrahedral structure of waterTetrahedral structure of water Cube structure of salt Cube structure of salt Hexagonal structure of carbon-carbon Hexagonal structure of carbon-carbon

interactionsinteractions

Tetrahedral Structure of Tetrahedral Structure of WaterWater

www.progressivegardens.com/growers_guide/www.progressivegardens.com/growers_guide/waterstructure.jpgwaterstructure.jpg

Chemical Forces Organize Chemical Forces Organize Self AssemblySelf Assembly

Strong Interactions at the chemical Strong Interactions at the chemical level will define some assembly level will define some assembly these include these include Covalent BondsCovalent Bonds

The sharing of electrons between atoms as in water.

Ionic bonds The formation of charged particles as in

salt.

Bond StructureBond Structure

www.accessexcellence.org/RC/VL/GG/ecb/www.accessexcellence.org/RC/VL/GG/ecb/covalent_ionic_bonds.htmlcovalent_ionic_bonds.html

Weak Chemical Weak Chemical InteractionsInteractions

Modify structure within moleculesModify structure within molecules Organize structure between Organize structure between

moleculesmolecules Examples include: Examples include:

Hydrogen bondsHydrogen bonds Van der Waals forcesVan der Waals forces Hydrophobic hydrophilic interactionsHydrophobic hydrophilic interactions

Hydrogen BondsHydrogen Bonds

Form when an electron negative atom Form when an electron negative atom usually one with more protons than usually one with more protons than another atom pulls the electrons away another atom pulls the electrons away from the smaller atom. from the smaller atom.

Leading to a charge separation with the Leading to a charge separation with the atom with the most protons having a atom with the most protons having a negative charge and the atom with the negative charge and the atom with the least protons having a positive charge. least protons having a positive charge. Most common when hydrogen is bonded to Most common when hydrogen is bonded to

a oxygen, nitrogen or fluorine atom.a oxygen, nitrogen or fluorine atom.

Hydrogen BondHydrogen Bond

http://academic.brooklyn.cuny.edu/biology/bio4fv/page/http://academic.brooklyn.cuny.edu/biology/bio4fv/page/image12.gifimage12.gif

Vander Waals ForcesVander Waals Forces

Are weak bonds between molecules Are weak bonds between molecules caused by the random fluctuations in caused by the random fluctuations in electrons.electrons.

The atoms within the molecules exist as The atoms within the molecules exist as transient dipoles.transient dipoles. One part has a weak negative charge

another part a weak positive charge. Example: water

Vander Waals ForcesVander Waals Forces

http://www.straightdope.com/mailbag/http://www.straightdope.com/mailbag/WaterPolarity.jpgWaterPolarity.jpg

Hydrophilic –Hydrophobic Hydrophilic –Hydrophobic InteractionsInteractions

Molecules can exist as polar and nonpolar Molecules can exist as polar and nonpolar molecules.molecules. Polar molecules have charges and interact with

other charged molecules. NaCl readily dissolves in water another charged molecule.

Nonpolar molecules do not have charges. Olive oil is an example. Nonpolar molecules readily dissolve in other nonpolar

molecules. Butter and olive oil will mix.

But do not readily dissolve in polar molecules. Oil and water do not mix.

This inability to mix leads to structure.

Hydrophilic –Hydrophobic Hydrophilic –Hydrophobic InteractionsInteractions

http://www.biologycorner.com/resources/http://www.biologycorner.com/resources/lipidbilayer.giflipidbilayer.gif

Forces of Chemical Forces of Chemical ReactionsReactions

Two forces control whether or not Two forces control whether or not reactions will occur spontaneously.reactions will occur spontaneously. Entropy - the amount of order in a system.Entropy - the amount of order in a system. Enthalpy – the energy found in the bonds Enthalpy – the energy found in the bonds

in the chemical reaction.in the chemical reaction. Chemical reactions occur spontaneously if Chemical reactions occur spontaneously if

the disorder in the system is increased the disorder in the system is increased (entropy) and the molecules) formed have (entropy) and the molecules) formed have less energy then the original molecules less energy then the original molecules (enthalpy).(enthalpy).

EntropyEntropy

www-lmmb.ncifcrf.gov/~toms/icons/www-lmmb.ncifcrf.gov/~toms/icons/s.harris-dep...s.harris-dep...

A Non Biological Forces A Non Biological Forces Can Lead to Self AssemblyCan Lead to Self Assembly

Magnetism – the power of attraction that Magnetism – the power of attraction that exists in materials such as iron.exists in materials such as iron.

Ferromagnetism is defined as the state Ferromagnetism is defined as the state when the relevant electron spins within a when the relevant electron spins within a material all point in the same direction. material all point in the same direction. Attraction of a metal to a magnet can lead to a

stable structure.

nanotechnologya\V_ H_ Crespi Magnetism @ Penn State Physics.htm

MagnetismMagnetism

http://www.teachnet-lab.org/ps101/bglasgold/magnetism/http://www.teachnet-lab.org/ps101/bglasgold/magnetism/magnetism2.jpgmagnetism2.jpg

Biological Materials used in Biological Materials used in Self Assembly Self Assembly

Nanotechnologists are using a Nanotechnologists are using a variety of biological materials to variety of biological materials to create nanostructures.create nanostructures.

These include:These include: Carbon based materials such as carbon Carbon based materials such as carbon

nanotubes and buckyballsnanotubes and buckyballs Proteins – enzymes and antibodiesProteins – enzymes and antibodies LipidsLipids DNADNA

Carbon based Carbon based NanostructuresNanostructures

Graphite nanotubesGraphite nanotubes were first were first discovered in 1991 by Sumio Iijima in discovered in 1991 by Sumio Iijima in Japan. Japan.

The carbon atoms in the tubes are The carbon atoms in the tubes are arranged in hexagons.arranged in hexagons.

Nanotubes can act as transistors, and Nanotubes can act as transistors, and pairs of nanotubes can act as logic pairs of nanotubes can act as logic structures. structures.

They have been added to golf balls, They have been added to golf balls, tennis rackets and other materials to tennis rackets and other materials to increase their strength .increase their strength .

Graphite (Carbon Graphite (Carbon Nanotube)Nanotube)

Note the hexagonal structures, Note the hexagonal structures, each point in the structure is a each point in the structure is a carbon atom.carbon atom.

http://www.nanotech-now.com/images/junction-http://www.nanotech-now.com/images/junction-large.jpglarge.jpg

Paper Battery of Paper Battery of NanotubesNanotubes

In August 2007 at RPI a paper was In August 2007 at RPI a paper was created using carbon nanotubes.created using carbon nanotubes. This paper can extract energy from This paper can extract energy from

human blood and sweat.human blood and sweat. The battery can be formed into many The battery can be formed into many

different shapes and it power increased different shapes and it power increased by adding more sheets of paperby adding more sheets of paper

Morgan, R. Amazing Battery made of Morgan, R. Amazing Battery made of Paper Discover January 2007 p.51Paper Discover January 2007 p.51

Carbon Nanotube Paper Carbon Nanotube Paper BatteryBattery

http://www.eurekalert.org/multimedia/pub/4801.php?http://www.eurekalert.org/multimedia/pub/4801.php?from=99678from=99678

BuckyballsBuckyballs Buckministerfulleren C60 or buckyballs Buckministerfulleren C60 or buckyballs

can be created by vaporizing carbon. can be created by vaporizing carbon. It consists of 60 atoms of carbon.It consists of 60 atoms of carbon.

Evidence of this carbon form was first Evidence of this carbon form was first published in 1985 in Nature by Kroto et published in 1985 in Nature by Kroto et al.al.

Their uses include:Their uses include: reinforcement, adding strength to reinforcement, adding strength to

substances.substances. Some are being used for drug release in Some are being used for drug release in

buckysomes.buckysomes.

Buckministerfulleren C60 Buckministerfulleren C60 or a Buckyballor a Buckyball

BuckysomeBuckysome

http://www.wipo.int/ipdl/IPDL-IMAGES/PCT-IMAGES/http://www.wipo.int/ipdl/IPDL-IMAGES/PCT-IMAGES/21082003/US0304416_21082003_gz_en.x4-b.jpg21082003/US0304416_21082003_gz_en.x4-b.jpg

The therapeutic agent The therapeutic agent attached to the buckysome.attached to the buckysome.

NanowireNanowire

A nanowire is an extremely thin wire A nanowire is an extremely thin wire with a diameter on the order of a with a diameter on the order of a few nanometers. few nanometers. Germanium and silicon nanowires can Germanium and silicon nanowires can

be made. be made. Function in lithographic printing and Function in lithographic printing and

silicon chips.silicon chips.

Uses of NanowiresUses of Nanowires

In 2007, orderly arrays of In 2007, orderly arrays of nanowires were grown on crystals nanowires were grown on crystals in a technique that could lead to in a technique that could lead to high density memory chips and high density memory chips and transparent LEDS.transparent LEDS.

Another use is a detector of Another use is a detector of cancer.cancer. The conductivity of the wire changes as it binds the

cancer proteins.Science News 172:334Science News 172:334 http://www.newstarget.com/012956.htmlhttp://www.newstarget.com/012956.html

Biological Compounds of Biological Compounds of NanoScience NanoScience

Proposed Biological Compounds include:Proposed Biological Compounds include: Proteins

Complex structure lets them have specific characteristics and shape.

Lipids Hydrophilic and hydrophobic interactions permit

them to assume specific shapes and to interact with the bodies of cells.

Nucleic Acids Their specific bonding permits the creation of

specific shape and the ability to change that shape under different conditions.

Proteins StructureProteins Structure

Proteins are created from amino Proteins are created from amino acidsacids The 20 amino acids found in nature The 20 amino acids found in nature

have unique properties.have unique properties. Some are acidic some are basic and some

are neutral. Long strings of amino acids form the basic

(primary) structure of a protein.

General Amino Acid General Amino Acid StructureStructure

Variation in the R group leads to Variation in the R group leads to acidic and basic and neutral amino acidic and basic and neutral amino acids.acids.

Marieb, E. and Hoehn, Human Anatomy and Physiology 7Marieb, E. and Hoehn, Human Anatomy and Physiology 7thth ed., 2007. Pearson Education, Inc. p. 49 ed., 2007. Pearson Education, Inc. p. 49

Bonds form Chains of Bonds form Chains of Amino Acids Amino Acids

Two amino acids join together in a Two amino acids join together in a peptide bond. peptide bond.

Marieb, E. and Hoehn, Human Anatomy and Physiology 7th Marieb, E. and Hoehn, Human Anatomy and Physiology 7th

ed., 2007. Pearson Education, Inc. p. 49ed., 2007. Pearson Education, Inc. p. 49

Protein folding Creates Protein folding Creates Three Dimensional Three Dimensional

StructureStructure Hydrogen bonds between the amino Hydrogen bonds between the amino

and carboxyl groups creates two and carboxyl groups creates two main forms of secondary protein main forms of secondary protein structure. structure. An alpha helix and a beta pleated sheet.An alpha helix and a beta pleated sheet.

Two main primary Two main primary structures of polypeptide structures of polypeptide

chains. chains. Two main secondary structures of Two main secondary structures of proteins.proteins.

Marieb, E. and Hoehn, Human Anatomy and Physiology Marieb, E. and Hoehn, Human Anatomy and Physiology 7th ed., 2007. Pearson Education, Inc. p. 517th ed., 2007. Pearson Education, Inc. p. 51

Proteins can create Unique Proteins can create Unique StructuresStructures

Enzymes and antibodies are unique Enzymes and antibodies are unique proteins that because of their proteins that because of their specific structure can only attach to specific structure can only attach to other unique structures.other unique structures. This ability makes them important to This ability makes them important to

nanotechnology because they can be nanotechnology because they can be used to bind and cause self assembly by used to bind and cause self assembly by joining together two or more joining together two or more substances. substances.

Structure of an AntibodyStructure of an Antibody Three dimensional antibody Three dimensional antibody

structurestructure The antigen binding site is where The antigen binding site is where

other substances bind. other substances bind.

Marieb, E. and Hoehn, Human Anatomy and Marieb, E. and Hoehn, Human Anatomy and Physiology 7th ed., 2007. Pearson Education, Inc. p. Physiology 7th ed., 2007. Pearson Education, Inc. p.

807807

Functions of Antibodies in Functions of Antibodies in NanoscienceNanoscience

Sensors for biological molecules, Sensors for biological molecules, bacteria and viruses.bacteria and viruses.

http://chemistry.nrl.navy.mil/6170/6177/http://chemistry.nrl.navy.mil/6170/6177/researchareas.phpresearchareas.php

The Y shaped structures are the The Y shaped structures are the antibodies.antibodies.

Molecular MotorsMolecular Motors

Protein molecules have been Protein molecules have been investigated as molecular motors.investigated as molecular motors.

Three of the proteins that have been Three of the proteins that have been studied include:studied include: FF11-F-F00 ATPase an enzyme ATPase an enzyme Kinesin and dyneinKinesin and dynein MyosinMyosin

FF11-F-F00 ATPase ATPase

Found in membranes of mitochondria, and chloroplasts in all living organisms.

The enzyme consists of 3 major units the F0 unit, the central stalk that connects the F0 motor to the F1 motor and the F1 motor .

The motor rotates one way during ATP production and the opposite way during ATP hydrolysis or break down.

To view a video on the function and structure of the ATPAse go to: http://multimedia.mcb.harvard.edu/media.html

Converting the ATPase to a Converting the ATPase to a NanoMotorNanoMotor

Monetemagno’ s Monetemagno’ s group modified the group modified the form of the ATPase.form of the ATPase. They attached it to a They attached it to a

metal surface by metal surface by modifying its protein modifying its protein structure.structure.

They added a metal They added a metal rotor so they could rotor so they could observe the rotation. observe the rotation.

ATPase MotorATPase Motor

Animation of ATPase Animation of ATPase MotorMotor

Molecular Model T Scientific Molecular Model T Scientific AmericanAmerican

http://www.sciam.com/article.cfm?http://www.sciam.com/article.cfm?articleID=000988D5-647B-1C75-articleID=000988D5-647B-1C75-9B81809EC588EF219B81809EC588EF21

Facts About the ATPase Facts About the ATPase MotorMotor

Efficiency of 80 -100%.Efficiency of 80 -100%. Can be turned on and off by adding a zinc Can be turned on and off by adding a zinc

binding site and removing zinc from the binding site and removing zinc from the system.system.

Relatively short life span.Relatively short life span. Could be used to generate electrical Could be used to generate electrical

current.current. Chip based drug delivery pumps. Chip based drug delivery pumps. Step in the right direction but probably not Step in the right direction but probably not

the motor of the future. the motor of the future.

Kinesin Linear MotorKinesin Linear Motor

Moves in discreet steps along Moves in discreet steps along microtubules in a specific direction microtubules in a specific direction depending on the polarity of the depending on the polarity of the microtubules.microtubules.

Can be used as a delivery device for the Can be used as a delivery device for the separation, sorting and assembly of separation, sorting and assembly of materials.materials.

Need to be able to guide the Need to be able to guide the transportation along specific pathways.transportation along specific pathways. Currently using enclosed fluidic channels.

Animation of the Motion of Animation of the Motion of KinesinKinesin

animation website animation website http://www.fli-leibniz.de/~khttp://www.fli-leibniz.de/~k

boehm/Kinesin.htmlboehm/Kinesin.html

Directed Movement of Directed Movement of KinesinKinesin

Using an electrical field researches Using an electrical field researches were able to direct the movement of were able to direct the movement of kinesin proteins to a given location.kinesin proteins to a given location.

Source: Dominiczak, P. Source: Dominiczak, P. Nanotoday 1 (3) Microtubules Nanotoday 1 (3) Microtubules Steered in the Right Direction Steered in the Right Direction

2006 p 102006 p 10

Dynein Dynein

Walks with a step size about thrice the Walks with a step size about thrice the size of kinesin. size of kinesin.

Dynein can shorten its stepsize.Dynein can shorten its stepsize. When a heavier load is added, When a heavier load is added,

however, a dynein motor changes however, a dynein motor changes gears This gives dynein more power to gears This gives dynein more power to pull the heavier cargo.pull the heavier cargo.

The dynein dynactin motor to move in The dynein dynactin motor to move in both directions along the microtubule.both directions along the microtubule.

Animation and Structure of Animation and Structure of the Protein Dyneinthe Protein Dynein

http://www.fbs.leeds.ac.uk/research/contractility/http://www.fbs.leeds.ac.uk/research/contractility/dynein/model-page.htmdynein/model-page.htm

Uses of Dynein in Uses of Dynein in NanotechnologyNanotechnology

Can be used to ferry cargo of Can be used to ferry cargo of different weights.different weights.

Can move cargo in 2 directions Can move cargo in 2 directions unlike kinesin.unlike kinesin.

Myosin V MotorMyosin V Motor

Protein that walks over actin Protein that walks over actin filaments.filaments.

Myosin MotorMyosin Motor Myosin V moves along actin Myosin V moves along actin

chains in a linear fashion.chains in a linear fashion. In a In a hand over handhand over hand

stepping mechanism one stepping mechanism one head domain dissociates head domain dissociates from an actin filament only from an actin filament only when the other head domain when the other head domain binds to the next subunit .binds to the next subunit .

Can be used to ferry Can be used to ferry materials in the cell.materials in the cell.

Motor ProteinsMotor Proteins

Motor proteins have a variety of Motor proteins have a variety of motions from linear to rotary.motions from linear to rotary.

Different movements can be used to Different movements can be used to manufacture machines with different manufacture machines with different characteristics.characteristics.

LipidsLipids

Neutral fats or triglycerides are Neutral fats or triglycerides are structures that can be used to create structures that can be used to create nanoscale particles.nanoscale particles.

Structure of a lipidStructure of a lipid Made up of fatty acids.Made up of fatty acids.

Long chains of hydrocarbons with one end terminated by a carboxyl group (COOH).

Three fatty acids can be combined with a Three fatty acids can be combined with a glycerol molecule to make a glycerol molecule to make a triglyceridetriglyceride. .

Properties of LipidsProperties of Lipids

The long chains of fatty acids make The long chains of fatty acids make the lipid hydrophobic, it does not the lipid hydrophobic, it does not readily dissolve in water .readily dissolve in water .

If one of the fatty acids is replaced If one of the fatty acids is replaced by a phosphate group the resulting by a phosphate group the resulting molecule a phospholipid has a molecule a phospholipid has a hydrophobic region (fatty acid) and a hydrophobic region (fatty acid) and a hydrophilic region (phosphate hydrophilic region (phosphate group). group).

This orients the molecule in water. This orients the molecule in water.

Phospholipid In Cell Phospholipid In Cell Membrane Membrane Phosphate groupsPhosphate groups (balls are oriented (balls are oriented

toward the water parts inside and toward the water parts inside and outside the cell).outside the cell).

www.biologycorner.com/www.biologycorner.com/resources/lipidbilayer.gifresources/lipidbilayer.gif

Uses of Lipids in Uses of Lipids in NanoscienceNanoscience

Liposomes – balls of phospholipids act as Liposomes – balls of phospholipids act as vehicles for the controlled delivery of vehicles for the controlled delivery of substances, such as drugs, genes, substances, such as drugs, genes, pesticides, cosmetics, and foodstuffs.pesticides, cosmetics, and foodstuffs. Fat soluble materials can be sequestered in Fat soluble materials can be sequestered in

the bilayer .the bilayer . Water soluble materials can be sequestered in Water soluble materials can be sequestered in

the interior.the interior. Antibodies embedded in the phospholipid Antibodies embedded in the phospholipid

membrane direct the site of fusion of the membrane direct the site of fusion of the liposome to the correct cells.liposome to the correct cells.

LiposomesLiposomes

http://www.uic.edu/classes/bios/bios100/lectf03am/http://www.uic.edu/classes/bios/bios100/lectf03am/liposome.jpgliposome.jpg

Liposome GelLiposome Gel

All of the active principles of the gel All of the active principles of the gel are extracted from are extracted from Ginkgo Ginkgo BilobaBiloba. It . It is able to penetrate into the deeper is able to penetrate into the deeper layers of the skin and helps to delay layers of the skin and helps to delay the visible signs of aging. the visible signs of aging.

http://www.make-upusa.com/skincare/http://www.make-upusa.com/skincare/liposomegel.htmliposomegel.htm

Nucleic acids in Nucleic acids in NanoscienceNanoscience

The precise structure of the nucleic acid The precise structure of the nucleic acid DNA makes it a good prospect for self DNA makes it a good prospect for self assembly in nanotechnology.assembly in nanotechnology. The ability to precisely order the molecules in The ability to precisely order the molecules in

the DNA molecule makes it possible to create the DNA molecule makes it possible to create specific structures.specific structures.

The machines to precisely create DNA and The machines to precisely create DNA and manipulate it already exist in the biotechnology manipulate it already exist in the biotechnology field.field.

The ability of the DNA molecule to change its The ability of the DNA molecule to change its gross structure under chemical conditions gross structure under chemical conditions makes it applicable for switches.makes it applicable for switches.

Structure of DNAStructure of DNA

The building blocks of the nucleic acids The building blocks of the nucleic acids are nucleotides consisting of a pentose are nucleotides consisting of a pentose sugar linked to a phosphate group and sugar linked to a phosphate group and organic base (thymine, guanine, organic base (thymine, guanine, cytosine, and adenine in DNA or cytosine, and adenine in DNA or guanine, cytosine, adenine and uracil in guanine, cytosine, adenine and uracil in RNA). RNA).

The phosphate groups link the sugars of The phosphate groups link the sugars of the nucleotides together forming long the nucleotides together forming long stands of DNA or RNA. stands of DNA or RNA.

Nucleotide StructureNucleotide Structure

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/nucleotide.gif

http://www.apsu.edu/robertsonr/chem1020/Image12.gifhttp://www.apsu.edu/robertsonr/chem1020/Image12.gif

Variations in the base Variations in the base create the 5 types of create the 5 types of

nucleotides. nucleotides.

Structure of DNAStructure of DNA

Two strands of DNA can bond Two strands of DNA can bond together using hydrogen bonds together using hydrogen bonds between base pairs. between base pairs. In DNA thymine always pairs with In DNA thymine always pairs with

adenine and cytosine always base pairs adenine and cytosine always base pairs with guanine via hydrogen bonds.with guanine via hydrogen bonds.

The most common form of DNA is the The most common form of DNA is the double helix. double helix.

It is called the B or right handed DNA It is called the B or right handed DNA structure.structure.

Structure of a Structure of a TriglycerideTriglyceride

Glycerol with three fatty acid Glycerol with three fatty acid molecules.molecules.

Marieb, E. and Hoehn, Human Anatomy and Physiology 7th Marieb, E. and Hoehn, Human Anatomy and Physiology 7th ed., 2007. Pearson Education, Inc. p. 47ed., 2007. Pearson Education, Inc. p. 47

Base Pairs of Nucleotides Base Pairs of Nucleotides and Double Helix of DNAand Double Helix of DNA

http://info.cancerresearchuk.org/images/gpimages/ys_DNA_4and5

Other forms of DNA Other forms of DNA

DNA can consist of left handed DNA can consist of left handed forms.forms. Combinations of left and right handed Combinations of left and right handed

forms.forms. Branched forms.Branched forms. Arrays of branched forms.Arrays of branched forms.

Structural Forms of DNAStructural Forms of DNA

Right (B) and left (Z) handed forms Right (B) and left (Z) handed forms of DNA.of DNA.

NormaNormal DNAl DNA

A DNA SwitchA DNA Switch

Combining the B and Z forms can Combining the B and Z forms can create a molecular switchcreate a molecular switch Under the correct chemical conditions Under the correct chemical conditions

the DNA can switch its form and the DNA can switch its form and orientation acting like a chemical orientation acting like a chemical switch. switch.

Structural Forms of DNAStructural Forms of DNA

Example of a 4 stranded form Example of a 4 stranded form of DNA.of DNA.

Seeman, N. 1999 Tibtech 17, 437-442.Seeman, N. 1999 Tibtech 17, 437-442.

http://www.halcyon.com/nanojbl/http://www.halcyon.com/nanojbl/NanoConProc/nanocon5.html#anchor344973NanoConProc/nanocon5.html#anchor344973

Branched DNA Molecules Branched DNA Molecules UsesUses

According to Seeman the branched According to Seeman the branched DNA molecules can be used to:DNA molecules can be used to: Create cages to orient other molecules Create cages to orient other molecules

(bricks plus mortar).(bricks plus mortar). If combined with metal atoms it can act as a If combined with metal atoms it can act as a

molecular wire.molecular wire. To orient the components of molecular To orient the components of molecular

electronics with precision (smart glue).electronics with precision (smart glue).

LaBean T. H. and Li, H. 2007 Nanotoday LaBean T. H. and Li, H. 2007 Nanotoday (2 (2), 26-35 Seeman, N. 1999 Tibtech 17, (2 (2), 26-35 Seeman, N. 1999 Tibtech 17,

437-442.437-442.

Expected Used For DNA Expected Used For DNA StructuresStructures

DNA computingDNA computing Patterning of nanomaterials, for sensors and Patterning of nanomaterials, for sensors and

bionanomachines.bionanomachines. Can be used to orient carbon nanotubes which is Can be used to orient carbon nanotubes which is

currently difficult. currently difficult. The nano sorter: DuPont uses DNA to sort carbon The nano sorter: DuPont uses DNA to sort carbon

nanotubes by conductivity. (Nanotech). nanotubes by conductivity. (Nanotech). Can also be attached to buckyballs.Can also be attached to buckyballs. Can be attached to proteins a such as antibodies Can be attached to proteins a such as antibodies

and enzymesand enzymes It is being used to create chips to probe for RNA. It is being used to create chips to probe for RNA.

Talbot, D. 2003 Technology ReviewTalbot, D. 2003 Technology Reviewhttp://www.smh.com.au/news/technology/researchers-make-http://www.smh.com.au/news/technology/researchers-make-

nanoscale-dna-research-tool/2008/01/11/1199988556980.htmlnanoscale-dna-research-tool/2008/01/11/1199988556980.html

Quantum DotsQuantum Dots

A A quantum dotquantum dot is a crystal a few is a crystal a few nanometers in diameter. nanometers in diameter. They can be made from a variety of They can be made from a variety of

metals including gold. metals including gold. They will shine a different color They will shine a different color

depending on their concentration and depending on their concentration and size.size.

Dots can be bound to a variety of Dots can be bound to a variety of materials and incorporated in films. materials and incorporated in films.

Quantum Dot FunctionQuantum Dot Function

Quantum dots function by moving electrons Quantum dots function by moving electrons from their valance band to the conduction from their valance band to the conduction band.band. When the electrons travel back to their valance When the electrons travel back to their valance

band they emit a characteristic wavelength of light.band they emit a characteristic wavelength of light. Decreasing the size of the quantum dot shifts the Decreasing the size of the quantum dot shifts the

size of the bandwidth between the valance band size of the bandwidth between the valance band and the conduction band.and the conduction band.

This shifts the light emitted further into the blue or higher This shifts the light emitted further into the blue or higher frequency range.frequency range.

Animation of how quantum dots work: Animation of how quantum dots work: http://www.evidenttech.com/quantum-dots-explained/180.http://www.evidenttech.com/quantum-dots-explained/180.html html

Uses Quantum DotsUses Quantum Dots

Next generation LEDs.Next generation LEDs.

Night vision pigments and inks.Night vision pigments and inks. Fluorescent inks can be added to Fluorescent inks can be added to

documents to prevent counterfeiting. documents to prevent counterfeiting.

http://www.evidenttech.com/applicationshttp://www.evidenttech.com/applications

Uses Quantum DotsUses Quantum Dots

Bioreagents to take the place of Bioreagents to take the place of stains and dyes can be used to locate stains and dyes can be used to locate specific proteins, antibodies and specific proteins, antibodies and DNA and RNA.DNA and RNA.

As components of solar cells. As components of solar cells.

Advantages of Self Advantages of Self Assembled NanotechnologyAssembled Nanotechnology

Ability to work at a much smaller Ability to work at a much smaller scale than ever before:scale than ever before: In medicineIn medicine In electronicsIn electronics In researchIn research

Ability to work with new materials Ability to work with new materials from biological organisms.from biological organisms.

Energy and materials savings.Energy and materials savings.

Cantilevered Biosensor Cantilevered Biosensor

Adding biological agents from Adding biological agents from antibodies to DNA and RNA makes it antibodies to DNA and RNA makes it possible to detect very small amount possible to detect very small amount of materials.of materials.

http://www.nccr-nano.org/nccr/research/http://www.nccr-nano.org/nccr/research/modules/module_01modules/module_01

Mobile Carbon Mobile Carbon Structures Structures

A molecular wheel A molecular wheel the turning can be the turning can be seen in the rotation seen in the rotation of the blue dots in of the blue dots in the top two framesthe top two frames

The molecule is The molecule is made from multiples made from multiples of a hydrocarbon of a hydrocarbon called triptycence.called triptycence.

http://www.nano.org.uk/Wheel.htmhttp://www.nano.org.uk/Wheel.htm

Challenges for Self Challenges for Self Assembled NanotechnologyAssembled Nanotechnology

Mass production with a high degree Mass production with a high degree of fidelityof fidelity

Finding a constant and consistent Finding a constant and consistent energy source at the nanoscale.energy source at the nanoscale.

Understanding how the biological Understanding how the biological world will treat materials its has world will treat materials its has only before seen created by only before seen created by biological means.biological means.