11-02/03 :: February / March 2011

nanotimes News in Brief

François Boily and Madeleine Ramstedt, were investigating whether new physiochemical analysis methods could also be used for microbial studies. The scientists combined so-called cryo-x-ray pho- toelectron spectroscopy with multivariate analysis. This analysis yields specific patterns of intensity curves depending on the chemical composition of the surface of the material being studied.

“We’ve succeeded also in analyzing the cell sur- faces of bacteria with our x-ray spectroscopy. We found strong patterns that we could clearly relate to different compositions in lipids, sugar, protein, and the polymer peptidoglycan in the cell wall of the bacterium that can affect the capacity of a bacte- rium to infect an organism,” explains Madeleine Ramstedt. “The method makes it possible to analyze the outermost layer, about 10nm from the surface.”

Madeleine Ramstedt, Ryoma Nakao, Sun Nyunt Wai, Bernt Eric Uhlin, and Jean-Francois Boily: Monitoring sur- face chemistry changes in the bacterial cell wall – multi- variate analysis of Cryo-X-ray photoelectron spectroscopy data, In: The Journal of Biological Chemistry, February 17, 2011, DOI:10.1074/jbc.M110.209536: http://dx.doi.org/10.1074/jbc.M110.209536

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technique, capable of detecting even single mole- cules, after decades of waiting in specialized labo- ratories has finally got a chance to widespread and revolutionize medical diagnostics.

SERS substrates designed by Polish researchers have unique properties. „The substrates commercially available so far had to be handled with extreme caution. They had to be stored under nitrogen, could not be touched and even though they were loosing their enhancement ability within hours only. Our substrates can be put into an ordinary drawer for a couple of months and they will be still usable” – stresses Ph.D. Agnieszka Michota- Kaminska from the IPS PAS. For economic reasons, it is important that Polish substrates are suitable for multiple use as the only ones worldwide. Their sur- face structure is so stable that the researchers from the IPC PAS were able to develop efficient cleaning procedures to assure that a high level of SERS signal enhancement is maintained.

The substrates for SERS studies have been develo- ped under the project „Quantum semiconductor nanostructures for applications in biology and medicine”.

Gold-coated substrates of gallium nitride with spe- cifically formed surface, developed by researchers from the Institute of Physical Chemistry of the Polish Academy of Sciences and the Institute of High Pressure Physics of the PAS display world- wide unique properties. Thanks to these new substrates, an extremely sensitive SERS analytical

One of the project’s long term goals is to develop a sensor for detection of antibodies in blood. The core element of the device will be a semiconductor with a surface network of thousands of micrometer size wells. http://www.ichf.edu.pl