Self-Assembly, Manipulation, and Discrimination of DNA Molecules by Scanning Tunneling Microscope (STM) on Solid Surfaces

The self-assembly of a series of cyclic oligo(phenylene-ethynylene) (OPE) molecules and their triangular Pt(ii) diimine complexes were studied using scanning tunneling microscope (STM).

Download Full-text

Mono-Atomic Tips and Scanning Tunneling Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100145169 ◽

1986 ◽

Vol 44 ◽

pp. 762-763

Author(s):

H.-W. Fink

Keyword(s):

Scanning Tunneling Microscope ◽

Sample Surface ◽

Solid Surfaces ◽

Scanning Tunneling ◽

Detailed Structure ◽

Tunneling Microscopy ◽

Tunnel Current ◽

Basic Principles ◽

Tunneling Microscope ◽

Distance Dependence

The power of the Scanning Tunneling Microscope (STM) to resolve the detailed structure of solid surfaces is based on the strong distance dependence of the tunnel current, while the tip is scanned over the surface to be investigated.In the first part of the paper, the basic principles of operation of the STM are to be reviewed, and examples of the information that can be obtained today are presented. From this, it will be evident that knowledge of the atomic arrangement of the tip is important in order to separate tunnel-current changes related to the tip from those owing to the structure of interest, namely, the sample surface.

Download Full-text

The Observation and Ultramicro-processing of Solid Surfaces by Scanning Tunneling Microscope

Corrosion engineering digest ◽

10.3323/jcorr1974.37.7_444 ◽

1988 ◽

Vol 37 (7) ◽

pp. 444-451

Author(s):

Kohei Uosaki

Keyword(s):

Scanning Tunneling Microscope ◽

Solid Surfaces ◽

Scanning Tunneling ◽

Tunneling Microscope

Download Full-text

Scanning tunneling microscopy of E. coli RNA polymerase deposited onto an Au substrate by an electrochemical process

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100086192 ◽

1991 ◽

Vol 49 ◽

pp. 378-379

Author(s):

Rebecca W. Keller ◽

Carlos Bustamante ◽

David Bear

Keyword(s):

Scanning Tunneling Microscope ◽

Biological Sample ◽

Substrate Surface ◽

Electrochemical Process ◽

Atomic Resolution ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

Tunneling Microscope ◽

E Coli ◽

Preparation Techniques

Under ideal conditions, the Scanning Tunneling Microscope (STM) can create atomic resolution images of different kinds of samples. The STM can also be operated in a variety of non-vacuum environments. Because of its potentially high resolution and flexibility of operation, it is now being applied to image biological systems. Several groups have communicated the imaging of double and single stranded DNA.However, reproducibility is still the main problem with most STM results on biological samples. One source of irreproducibility is unreliable sample preparation techniques. Traditional deposition methods used in electron microscopy, such as glow discharge and spreading techniques, do not appear to work with STM. It seems that these techniques do not fix the biological sample strongly enough to the substrate surface. There is now evidence that there are strong forces between the STM tip and the sample and, unless the sample is strongly bound to the surface, it can be swept aside by the tip.

Download Full-text

STM of freeze-fracture replicas: Problems and promises

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100146187 ◽

1993 ◽

Vol 51 ◽

pp. 68-69

Author(s):

J. T. Woodward ◽

J. A. N. Zasadzinski

Keyword(s):

Scanning Tunneling Microscope ◽

Organic Materials ◽

Freeze Fracture ◽

Atomic Resolution ◽

Scanning Tunneling ◽

Tunneling Microscope ◽

Molecular Scale ◽

Organic Surfaces ◽

Metal Layers ◽

Conductive Surfaces

The Scanning Tunneling Microscope (STM) offers exciting new ways of imaging surfaces of biological or organic materials with resolution to the sub-molecular scale. Rigid, conductive surfaces can readily be imaged with the STM with atomic resolution. Unfortunately, organic surfaces are neither sufficiently conductive or rigid enough to be examined directly with the STM. At present, nonconductive surfaces can be examined in two ways: 1) Using the AFM, which measures the deflection of a weak spring as it is dragged across the surface, or 2) coating or replicating non-conductive surfaces with metal layers so as to make them conductive, then imaging with the STM. However, we have found that the conventional freeze-fracture technique, while extremely useful for imaging bulk organic materials with STM, must be modified considerably for optimal use in the STM.

Download Full-text

The atomic-force microscope and its future in biology

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100149350 ◽

1993 ◽

Vol 51 ◽

pp. 704-705

Author(s):

Jean-Paul Revel

Keyword(s):

Silicon Nitride ◽

Laser Beam ◽

Atomic Force Microscope ◽

Scanning Tunneling Microscope ◽

Point Of View ◽

Scanning Tunneling ◽

Close Relative ◽

Tunneling Microscope ◽

Atomic Force ◽

Sharp Point

The last few years have been marked by a series of remarkable developments in microscopy. Perhaps the most amazing of these is the growth of microscopies which use devices where the place of the lens has been taken by probes, which record information about the sample and display it in a spatial from the point of view of the context. From the point of view of the biologist one of the most promising of these microscopies without lenses is the scanned force microscope, aka atomic force microscope.This instrument was invented by Binnig, Quate and Gerber and is a close relative of the scanning tunneling microscope. Today's AFMs consist of a cantilever which bears a sharp point at its end. Often this is a silicon nitride pyramid, but there are many variations, the object of which is to make the tip sharper. A laser beam is directed at the back of the cantilever and is reflected into a split, or quadrant photodiode.

Download Full-text