To Study Biological Molecules and Structures

August 31, 2009

Researchers in the United States and Spain have discovered that a tool widely used in nanoscale imaging works differently in watery environments, a step toward better using the instrument to study biological molecules and structures.

The researchers demonstrated their new understanding of how the instrument – the atomic force microscope – works in water to show detailed properties of a bacterial membrane and a virus called Phi29, said Arvind Raman, a Purdue professor of mechanical engineering. An atomic force microscope uses a tiny vibrating probe to yield information about materials and surfaces on the scale of nanometers, or billionths of a meter. Because the instrument enables scientists to „see“ objects far smaller than possible using light microscopes, it could be ideal for studying molecules, cell membranes and other biological structures. The best way to study such structures is in their wet, natural environments. However, the researchers have now discovered that in some respects the vibrating probe’s tip behaves the opposite in water as it does in air, said Purdue mechanical engineering doctoral student John Melcher. The probe is caused to oscillate by a vibrating source at its base. However, the tip of the probe oscillates slightly out of synch with the oscillations at the base. This difference in oscillation is referred to as a „phase contrast,“ and the tip is said to be out of phase with the base.

Although these differences in phase contrast reveal information about the composition of the material being studied, data can’t be properly interpreted unless researchers understand precisely how the phase changes in water as well as in air, Raman said.

If the instrument is operating in air, the tip’s phase lags slightly when interacting with a viscous material and advances slightly when scanning over a hard surface. Now researchers have learned the tip operates in the opposite manner when used in water: it lags while passing over a hard object and advances when scanning the gelatinous surface of a biological membrane.

Researchers deposited the membrane and viruses on a sheet of mica. Tests showed the differing properties of the inner and outer sides of the membrane and details about the latticelike protein structure of the membrane. Findings also showed the different properties of the balloonlike head, stiff collar and hollow tail of the Phi29 virus, called a bacteriophage because it infects bacteria.

Original Publication:

Melcher J, Carrasco C, Xu X, Carrascosa JL, Gómez-Herrero J, José de Pablo P, Raman A. (2009): Origins of phase contrast in the atomic force microscope in liquids. Proc Natl Acad Sci U S A. 2009 Aug 18;106(33):13655-60. Epub 2009 Aug 5.

Researchers in the United States and Spain have discovered that an atomic force microscope - a tool widely used in nanoscale imaging - works differently in watery environments, a step toward better using the instrument to study biological molecules and structures. The researchers demonstrated their new understanding of how the instrument works in water to show details of the mechanical properties of a virus called Phi29. The images in "a" and "c" show the topography, and the image in "b" shows the different stiffness properties of the balloonlike head, stiff collar and hollow tail of the Phi29 virus, called a bacteriophage because it infects bacteria. (C. Carrasco-Pulido, P. J. de Pablo, J. Gomez-Herrero, Universidad Autonoma de Madrid, Spain)

Researchers in the United States and Spain have discovered that an atomic force microscope - a tool widely used in nanoscale imaging - works differently in watery environments, a step toward better using the instrument to study biological molecules and structures. The researchers demonstrated their new understanding of how the instrument works in water to show details of the mechanical properties of a virus called Phi29. The images in "a" and "c" show the topography, and the image in "b" shows the different stiffness properties of the balloonlike head, stiff collar and hollow tail of the Phi29 virus, called a bacteriophage because it infects bacteria. (C. Carrasco-Pulido, P. J. de Pablo, J. Gomez-Herrero, Universidad Autonoma de Madrid, Spain)

http://news.uns.purdue.edu


Canada Gains New Centre for Nanotechnology

Juli 20, 2009

Alberta, Canada will soon be home to a new research and product development centre for nanotechnology called Hitachi Electron Microscopy Products Development Centre (HEMiC) at the National Institute for Nanotechnology (NINT) in Edmonton. The centre will house three new electron microscopes valued at $7 million. The $14 million project is supported by the Western Economic Partnership Agreement between the Governments of Canada and Alberta and to contributions from Hitachi High-Technologies. The HEMiC is made possible by a wider collaboration of the Alberta Ingenuity Fund’s nanoWorks program, the National Institute for Nanotechnology of the National Research Council, the University of Alberta and Hitachi High Technologies Canada Inc. One of the centre’s first projects will evaluate and test the world’s sharpest electron emitter, developed by the Molecular Scale Devices group at NINT for use as an electron source in electron microscopes.
www.nrc-cnrc.gc.ca


FEI Joins Metrology Research at University of Albany

Juli 15, 2009

FEI Company, a provider of atomic-scale imaging and analysis systems, and Sematech, the global consortium of chipmakers, announced that FEI has joined Sematech’s Advanced Metrology Development Program at the College of Nanoscale Science and Engineering (CNSE) of the University at Albany, US. As a member of this program, FEI will collaborate with experts to develop high-resolution capabilities of transmission electron microscopy (TEM) analysis, with electron energy loss spectroscopy (EELS) and focused ion beam (FIB) technology to address critical needs in process development and defect analysis.
www.fei.com
www.cnse.albany.edu
www.sematech.org


Milestone for Nanoelectronics

Juni 16, 2009

In collaboration with the University of Regensburg, Germany, and Utrecht University, Netherlands, IBM scientists demonstrated the ability to measure the charge state of individual atoms using noncontact atomic force microscopy. They imaged and identified differently charged individual gold and silver atoms by measuring the tiny differences in the forces between the tip of an atomic force microscope and a charged or uncharged atom located in close proximity below it. This opens up new possibilities in the exploration of nanoscale structures and devices at the ultimate atomic and molecular limits. These results hold potential to impact a variety of fields such as molecular electronics, catalysis or photovoltaics.
www.ibm.com/us/en/


International Nanoscience Conference

Februar 16, 2009

Veeco Instruments has announced it will host the seventh „Seeing at the Nanoscale“ conference at the University of California, Santa Barbara (UCSB), July 28-31, 2009. The conference provides a forum for academic and industrial scientists to share information and exchange ideas on advanced nanotechnology topics, ranging from novel imaging approaches and unique material characterization to combining atomic force microscopy (AFM) with other technologies, such as confocal microscopy and raman spectroscopy. This year there is also a special session on emerging AFM markets, such as energy generation, storage and conservation.
www.veeco.com/nanoconference
www.ucsb.edu


London Travel in Miniature

Februar 12, 2009

Researchers at Bio Nano Consulting (BNC), London, UK, have produced a miniaturized version of the London tube map, measuring only 2×3 mm. The map was etched using lasers by Dr Richard Winkle, a BNC researcher at Imperial College London, whilst testing the capabilities of a laser micromachining system. The ‚London Nanotube‘ was aptly named as nanotubes are an essential building block for nanotechnology. Dr Mike Fisher, business development director of BNC commented, „This version of the London Nanotube is not strictly on the nanoscale. We believe we can shrink the tube map another 100 times, making it invisible to the naked eye.“
www.bio-nano-consulting.com
www.imperial.ac.uk

The London Nanotube

The London Nanotube