nanotechnology n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Nanotechnology PowerPoint Presentation
Download Presentation
Nanotechnology

Loading in 2 Seconds...

play fullscreen
1 / 34

Nanotechnology - PowerPoint PPT Presentation


  • 569 Views
  • Uploaded on

Nanotechnology. What is nano? Nanotechnology?. Creation of nanostructures Applications of the nanostructures. Nanofabrication techniques.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Nanotechnology' - adamdaniel


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
nanotechnology
Nanotechnology
  • What is nano?
  • Nanotechnology?

Creation of nanostructures

Applications of the nanostructures

nanofabrication techniques
Nanofabrication techniques

Y.-P. Zhao, “Growth and Synthesis of Nanostructured Thin Films,” in “Functional Thin Films and Nanostructures for Sensors” edited by A. Zribi and J. Fortin (Springer, 2008)

top down
Top-down
  • Photo lithography
  • Electron beam lithography
  • Microcontact printing
  • Nanoimprint
  • Nanosphere lithography?
  • And so on…

Mask or maskless ?

bottom up

Han, J.T. et al. J. Am. Chem. Soc.,126 (15), 4796 -4797, 2004

Combination of top-down and bottom-up methods

Hah, J. H. et al.J. Vac. Sci. Technol. B (2006). 10.1116/1.2244541

Bottom-up

  • Supramolecular assembly
  • nanoparticle formation
  • monolayer self-assembly

The dividing line of top-down and bottom-up sometime is vague and it is

only a matter of opinion

thermo vapor transport method
Thermo-vapor transport method

A general setup for thermal-vapor transport method

catalyst assisted fabrication
Catalyst-assisted fabrication

Deposition of a catalyst layer, e.g. thermal evaporation of a 10 nm thick metal film

or injection of a precursor which decomposes into particles

ZnO nanorods on Au and NiO catalysts

slide11
Thermal evaporation (resistively, electron beam)
  • Sputtering (gas ion bombardment)
  • Pulsed laser deposition (laser beam)
chemical vapor deposition cvd
Chemical Vapor Deposition (CVD)

Reactant gases

Precursors/carrier gas

Laser beam or plasma can be introduced to enhanced the reaction

Can fabricate: carbon nanotubes, inorganic oxide nanorods, nanowire etc.

liquid phase methods
Liquid Phase Methods
  • Sol-gel dip-coating
  • Electro-spin coating
  • Block-copolymer
  • Electro-chemical deposition/etching
applications
Applications

Just name a few

  • Biosensor
  • Chemical sensor
  • Drug delivery
  • Self-cleaning
  • Energy harvesting

biosensor bacterial virus detection

dye

+

target

target

antibody

Conventional fluorescence antibody method

gold

antibody

+

Si nanorods

dye

Enhanced fluorescence antibody method

The fluorescence signal will be greatly enhanced by a large amount of dye molecules on the nanorods.

Biosensor bacterial/virus detection

Thank the author for sharing her research results

Junxue Fu et al 2008 Nanotechnology19 155502

slide20

What are these dark dots and what is the material?

SEM image of Si nanorods: top view and side view

TEM image of Au coated Si nanorods

dye immobilization on au si nanorods

NH2

NH2

45˚C, overnight

NH2

NH2

+

2% (3-Aminopropyl)triethoxysilane (APTES) in Acetone

O

C

N

H

C

1 hour at room temperature and overnight at 4°C

+

O

Alexa488-succinimide ester

NH

Wash by DI water

Dye immobilization on Au/Si Nanorods
slide23

Observation under fluorescence microscope

Do sonication in DI water

Fluorescence Scan

Si film/Alexa488 IF

Si rods/ Alexa488 IR

salmonella detection
Salmonella detection

Sample: Anti-Sal/Au/Si nanorods/Alexa488/2%BSA + Salmonella

Control: Au/Si nanorods/Alexa488/2%BSA + Salmonella

The bacteria were fixed on the glass slides by 95% ethanol. The unbound nanorods should be washed away by 0.05% Tween 20/FA buffer after the incubation.

slide25

Sample: Anti-Sal/Au/Si nanorods/Alexa488/2%BSA

Fluorescence Scan 532nm(ex.)/526nm SP emission filter

Fluorescence image

Bright field image

The Alexa488 labeled nanorods (darker particles) stick on the bacteria due to the antibody-antigen interaction.

slide26

Salmonella detection

Control: Au/Si nanorods/Alexa488/2%BSA

The control shows there is no fluorescence signal since the nanorods cannot attach to the bacteria without the antibody.

Fluorescence Scan 532nm(ex.)/526nm SP emission filter

Fluorescence image

Bright field image

slide27

Lotus effect: self cleaning

A

Barthlot et al. Planta 202, 1 (1997)

Feng et al. Adv, Mater. 14, 1857 (2002)

motivation
Motivation

wings of a Cicada orni

Water strider’s leg

Gao et al. Nature 36, 432(2004)

Lee et al. Langmuir 20, 7665 (2004)

slide29

165o

Tune the nanorod coverage

Si coverage f ~ 32%

Si coverage f ~ 48%

Deposition angle = 84o

Deposition angle = 88o

After coating a fluorocarbon monolayer

148o

water droplets bounce on a sold surface
Water droplets bounce on a sold surface

Water droplets impacting a superhydrophobic surface vs. a normal hydrophobic surface

slide32

Challenge?

Nonspecific binding can lead to false signal

slide33

Au nanoparticle for in vivo tumor targeting

PEG is a popular polymer in the pharmaceutical industry for reducing nonspecific uptake of drugs and drug-delivery systems

Qian et al. Nature Biotechnology