In The Name of Allah Scanning Tunneling Microscope Pooria Gill Ph.D. of Nanobiotechnology Faculty of...
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In The Name of Allah Scanning Tunneling Microscope Pooria Gill Ph.D. of Nanobiotechnology Faculty of Medicine Mazandaran University of Medical sciences
In The Name of Allah Scanning Tunneling Microscope Pooria Gill
Ph.D. of Nanobiotechnology Faculty of Medicine Mazandaran
University of Medical sciences [email protected]
Slide 2
Microscopy Optical Microscopy Scanning Electron Microscopy
Scanning Probe Microscopy
Slide 3
Scanning Probe Microscope Atomic Force Microscope (AFM)
Electrostatic Force Microscope (EFM) Magnetic Force Microscope
(MFM) Scanning Tunneling Microscope (STM) Near-field Scanning
Optical Microscope (SNOM)
Slide 4
History The scanning tunneling microscope was developed at IBM
Zrich in 1981 by Gerd Binning and Heinrich Rohrer who shared the
Nobel Prize for physics in 1986 because of the microscope. Gerd
BinningHeinrich Rohrer
Slide 5
The STM is an electron microscope that uses a single atom tip
to attain atomic resolution. Scanning Tunneling Microscope
(STM)
Slide 6
SPM Systems SPM Systems Piezoelectric Scanner
Slide 7
General Overview An extremely fine conducting probe is held
about an atoms diameter from the sample. Electrons tunnel between
the surface and the tip, producing an electrical signal. While it
slowly scans across the surface, the tip is raised and lowered in
order to keep the signal constant and maintain the distance. This
enables it to follow even the smallest details of the surface it is
scanning.
Slide 8
The Tip As we will see later, is very important that the tip of
the probe be a single atom. Tungsten is commonly used because you
can use Electro-chemical etching techniques to create very sharp
tips like the one above.
Slide 9
Note A STM does not measure nuclear position directly. Rather
it measures the electron density clouds on the surface of the
sample. In some cases, the electron clouds represent the atom
locations pretty well, but not always.
Slide 10
Converse Piezoelectricity Piezoelectricity is the ability of
certain crystals to produce a voltage when subjected to mechanical
stress. When you apply an electric field to a piezoelectric
crystal, the crystal distorts. This is known as converse
piezoelectricity. The distortions of a piezo is usually on the
order of micrometers, which is in the scale needed to keep the tip
of the STM a couple Angstroms from the surface. The tip Pizos
Electric Field
Slide 11
Scanning Modes Scanning Modes STM Constant Current Mode
Slide 12
STM Constant Height Mode
Slide 13
System Components System Components Mechanical Parts
Electronics Parts Computer + software
Advantages of Scanning Probe Microscopy The resolution of the
microscopesThe resolution of the microscopes Create small
structures nanolithographyCreate small structures nanolithography
Do not require a partial vacuumDo not require a partial vacuum
Disadvantages of Scanning Probe Microscopy The detailed shape of
the scanning tip The detailed shape of the scanning tip Slower in
acquiring images Slower in acquiring images The maximum image size
The maximum image size
Single strand of calf thymus DNA deposited along a surface step
of HOPG. (50 x 50 nm, constant current mode, current 0.1 nA, bias
voltage 500 mV.) Methods In Molecular Biology, Vol 22. Microscopy,
Opt/cat Spectroscopy, and Macmscop/c Technrqoes Edlted by: C Jones,
I3 Mulloy, and A H. Thomas Copynght 01994 Humana Press Inc.,
Totowa, NJ.
Slide 22
STM of -DNA (GeneRuler DNA) on HOPG P. Gill, B. Ranjbar, R.
Saber. IET Nanobiotechnol., 2011, Vol. 5, Iss. 1, pp. 813.
Slide 23
3D image of a single antibody (IgG) molecule after the
filtering and coloring process, which shows orientation of this
molecule after physical adsorption on the rigid surface from the
hinge region imaged by NAMA-STM R. Saber, S. Sarkar, P. Gill, B.
Nazari, F. Faridani. Scientia Iranica F (2011) 18 (6),
16431646.
Slide 24
3D image of a single antibody (IgM) molecule, imaged by
NAMA-STM. (b) Standard configuration of human immunoglobulin M with
pentameric domains R. Saber, S. Sarkar, P. Gill, B. Nazari, F.
Faridani. Scientia Iranica F (2011) 18 (6), 16431646.
Slide 25
STM comparison of passive antibody adsorption and biotinylated
antibody linkage to streptavidin on microtiter wells STM images of
antiferritin antibodies passively adsorbed to a microwell surface
STM images of biotinylated antiferritin antibodies immobilized to a
streptavidin coated microwell surface Davies et al., Journal of
Immunological Methods, 167 (1994) 263-269.
Slide 26
Individual Peptide Structures Visible by STM
Slide 27
Reconstructed surface topography of coated T4 polybead
capsomeres; (a) the TEM and (b) STM representations. The slight
variation in the representation may be due to the overlying carbon
film, which is observed by STM but not by TEM. Height range is 2.3
nm. (Reprinted with permission from Stemmer et al., 1989.) M.
FIRTEL and T. J. BEVERIDGE. Scanning Probe Microscopy in
Microbiology. Micron, Vol. 26, No. 4, pp. 347-362, 1995.
Slide 28
References References 1.Pooria Gill, Bijan Ranjbar, Reza Saber.
Scanning Tunneling Microscopy of Cauliflower-like DNA
Nanostructures Synthesized by Loop-mediated Isothermal
Amplification. IET Nanobiotechnology 2011; 5 (1), 8-13. 2.Reza
Saber, Saeed Sarkar, Pooria Gill, Behzad Nazari, Faramarz Faridani.
High Resolution Imaging of IgG and IgM Molecules by Scanning
Tunneling Microscopy in Air Condition. Scientia Iranica
(Transaction F: Nanotechnology) 2011; 18 (6), 16431646. 3.M.Q. Li.
Scanning probemicroscopy (STM=AFM) and applications in biology,
Appl. Phys. A 68, 255 258 (1999). 4.Errez Shapir et al.,
High-Resolution STM Imaging of Novel Single G4-DNA Molecules, J.
Phys. Chem. B, Vol. 112, No. 31, 2008. 5.D. P. ALLISON.
Immobilization of DNA for scanning probe microscopy, Proc. Nadl.
Acad. Sci. USA, Vol. 89, pp. 10129-10133, November 1992. 6.Hiroyuki
Tanaka. Visualization of the Detailed Structure of Plasmid DNA, J.
Phys. Chem. B 16788 2008, 112, 1678816792. 7.Hiroyuki Tanaka.
High-resolution scanning tunneling microscopy imaging of DNA
molecules on Cu(111) surfaces, Surface Science 432 (1999) L611L616.
8.Handbook of microscopy for nanotechnology / edited by Nan Yao.
Zhong Lin Wang. 2005 Kluwer Academic Publishers. 9.Scanning probe
microscopes : applications in science and technology / K.S. Birdi.
2003 by CRC Press LLC. 10.SCANNING PROBE MICROSCOPY, 2007 Springer
Science+Business Media, LLC.
Slide 29
Thanks for your Attentions Mazandaran University of Medical
Sciences and Health Care Sari, I.R. Iran www.mazums.ac.ir