Publications de Dusan Vobornik

Toward an Effective Control of DNA's Submolecular Conformation on a Surface

Giovanni Dietler, Dusan Vobornik, Aleksandre Japaridze, Andrea Cerreta, Ewelina Wioletta Lipiec

DNA adopts different conformations based on its environment. We reveal conditions that either preserve the DNA's physiological B-conformation, even upon its placement in UHV, or lead to a partial B-form to A-form reorganization upon DNA's deposition on a s ...

American Chemical Society2016

Real-Time Monitoring of Protein Conformational Changes Using a Nano-Mechanical Sensor

Giovanni Dietler, Paolo De Los Rios, Sandor Kasas, Giovanni Longo, Dusan Vobornik, Fabrizio Benedetti, Livan Bladimir Alonso Sarduy

Proteins can switch between different conformations in response to stimuli, such as pH or temperature variations, or to the binding of ligands. Such plasticity and its kinetics can have a crucial functional role, and their characterization has taken center ...

Public Library of Science2014

Fine DNA structure revealed by constant height frequency modulation AFM imaging

Giovanni Dietler, Dusan Vobornik, Andrea Cerreta

Few examples of sub nanometer resolution on biomolecules can be found in literature. In particular, AFM experiments on DNA mostly fail to show the double helical groove periodicity, and so far such a feat was only achieved in liquid. Here we describe a met ...

Elsevier2013

FM-AFM constant height imaging and force curves: high resolution study of DNA-tip interactions

Giovanni Dietler, Susana del Carmen Tobenas Borron, Dusan Vobornik, Livan Bladimir Alonso Sarduy, Andrea Cerreta

Interaction of the atomic force microscopy (AFM) tip with the sample can be invasive for soft samples. Frequency Modulation (FM) AFM is gentler because it allows scanning in the non-contact regime where only attractive forces exist between the tip and the ...

Wiley-Blackwell2012

Fluorescence correlation spectroscopy with sub-diffraction-limited resolution using near-field optical probes

Dusan Vobornik

We report fluorescence correlation spectroscopy (FCS) measurements using near-field scanning optical microscopy (NSOM) probes to produce a sub-diffraction-limited observation area. An order of magnitude reduction in the area compared to confocal FCS has be ...

American Institute of Physics2008

Chemical Mapping of Ceramide Distribution in Sphingomyelin-Rich Domains in Monolayers

Dusan Vobornik

The incorporation of ceramide in phase-separated monolayers of ternary lipid mixtures has been studied by a combination of atomic force microscopy (AFM), fluorescence, and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Replacement of a fraction ...

American Chemical Society2008

Low-frequency electromagnetic field effects on functional groups in human skin keratinocytes cells revealed by IR-SNOM

Giorgio Margaritondo, Dusan Vobornik

Human HaCaT cells, exposed for 24 h to a 1 mT (rms) 50 Hz sinusoidal magnetic field in a temperature-regulated solenoid, suffer detectable changes in their biochemical properties and shapes. By using infrared wavelength-selective scanning near-field optica ...

2008

Scanning near-field infrared microscopy and spectromicroscopy applied to nano-systems and cells

Dusan Vobornik

This thesis further explores the possibilities of scanning near-field optical microscopy (SNOM) in both materials and life sciences. Two experimental SNOM setups were developed: one designed for infrared spectroscopy applications and the other for the imag ...

EPFL2005

Spectroscopic infrared scanning near-field optical microscopy (IR-SNOM)

Giorgio Margaritondo, Dusan Vobornik

Scanning near-field optical microscopy (SNOM or NSOM) is the technique with the highest lateral optical resolution available today, while infrared (IR) spectroscopy has a high chemical specificity. Combining SNOM with a tunable IR source produces a unique ...

Elsevier2005