A lecture by Professor Nicolas B. Bercu (University of Reims Champagne-Ardenne) at an LNBE seminar: Modern methods of near-field microscopy for analyzing nanostructures

Nicolas Bogdan Bercu, a professor of the University of Reims Champagne-Ardenne, France, gave a lecture on Near-Field Microscopy Techniques for Nanostructure Characterization: Near-Field IR, AFM Nanomechanics, SEM/TEM Cathodoluminescence and Kelvin Probe Force Microscopy at an LNBE seminar on December 9.

Atomic force microscopy (AFM) is well known to have undeniable advantages over other methods in analyzing nanosized heterostructures: it is nondestructive, has a high resolution, requires only minor preparation of samples, and can be used in both air and liquid media while providing the researcher with information on a wide range of the sample's physical characteristics. On the other hand, AFM is unsuitable for chemical analysis of the sample and is rather time-consuming.

Professor Bercy and his research team have managed to overcome these disadvantages of AFM by combining it with near-field IR spectroscopy and other near-field microscopic and spectroscopic techniques. This allows them to obtain important data on the correlations between the nanoscale mechanical characteristics and chemical compositions of various materials.

For instance, they have characterized the nanostructure of the plant cell wall and the distribution of lignin, the substance determining the wood strength, between different parts of the cell wall.

Another example of the promising combination of AFM with IR spectroscopy is the estimation of the local concentrations of amyloid fibrils (aggregated peptides and proteins presumably accounting for a number of neurodegenerative disorders) in different areas of nervous tissue and analysis of the molecular and cellular mechanisms of their toxic effect.

Furthermore, a new technique of Kelvin probe force microscopy and a method for cathodoluminescence mapping have been developed for analysis of the nanoscale topography of samples.

While preserving the high resolution of the classical AFM, the new methods considerably extend its applications, allowing single-step analysis of a large number of physical, morphological, and chemical parameters of various materials, from live tissues to nanotechnology products.

Contacts:

Konstantin E. Mochalov, PhD, senior researcher (mochalov@mail.ru)

Laboratory of Nano-Bioengineering, Moscow Engineering Physics Institute
31 Kashirskoe shosse, 115409 Moscow, Russian Federation (http://www.lnbe.mephi.ru/en)

Prof. Nicolas Bogdan Bercu (nicolae-bogdan.bercu@univ-reims.fr)

 
 
 
© 2012 Laboratory of Nano-BioEngineering