Report on the Characterisation of Nanostructures and Nanosized Systems using AFM

JPK Instruments reports on how the NanoWizard AFM is being applied in the study of nanostructures and nano-sized systems at the École Polytechnique Federale de Lausanne.

Dr Giovanni Longo is a Research Scientist in the LPMV under the supervision of Professor Giovanni Dietler. He works on a number of projects which require the accuracy and reproducible performance at high resolution of an atomic force microscope, AFM, and has chosen the JPK NanoWizard® 3 for his work. For example, he uses the AFM cantilevers for the rapid detection of bacterial resistance to antibiotics. Living, moving specimens are attached to an AFM cantilever and their movements are transduced by the lever to the AFM electronics and recorded.

Describing this work, Dr Longo said "We recently moved this activity to the JPK NanoWizard microscope since it demonstrated an excellent sensitivity and since the optical microscope is invaluable to couple the macroscopic movements of the biological systems with the microscopic movements we detect using our nanomotion sensor."

Dr Longo describes a second project. "We also study osteoblasts for bone-integration and to characterise their response to microgravity conditions. In this field of research we have coupled the fluorescence microscopy capabilities of the Axiovert inverted microscope with the high-resolution AFM images to obtain stunning images of cells."

There are three main features of the NanoWizard which makes it the ideal tool for AFM studies. First, it operates with remarkable stability and the images it delivers are of high-quality and with a very high rate of repeatability. This is particularly impressive since the X/Y/Z ranges are not small and yet the images are of excellent quality both at very large and at very small ranges.

The JPK Quantitative Imaging mode (QI™) is excellent allowing fast imaging of the specimens while, at the same time, collecting their mechanical properties. This is invaluable especially when characterising many samples or when a large number of cells must be probed. For example, Dr Longo used it to determine the stiffness of hundreds of bacteria in different environmental conditions in just a few weeks.

Lastly, when the microscope is coupled with an excellent optical inverted microscope, it is capable of fluorescence imaging.