Publications de Volodymyr Koman

Non-invasive continuous monitoring of pro-oxidant effects of engineered nanoparticles on aquatic microorganisms

Olivier Martin, Paul Bowen, Christian Santschi, Volodymyr Koman, Nadia Rachel Von Moos

Engineered nanomaterials (ENMs) are key drivers for the development of highly sophisticated new technologies. As all new attainments, the rapidly increasing used of ENMs raise concerns about their safety for the environment and humans. There is growing evi ...

2017

Maximal absorption regime in random media

Olivier Martin, Christian Santschi, Volodymyr Koman

Efficient optical energy transfer is key to many technologies, ranging from biosensing to photovoltaics. Here, for the first time we show that by introducing a random medium with appropriate filling factor, absorption in a specific volume can be maximized. ...

Optical Society of America2016

New insights into ROS dynamics: a multi-layered microfluidic chip for ecotoxicological studies on aquatic microorganisms

Olivier Martin, Christian Santschi, Volodymyr Koman, Nadia Rachel Von Moos

Reactive oxygen species (ROS) play an important role in the life of every cell, including cellular defense and signaling mechanisms. Continuous and quantitative ROS sensing can provide valuable information about the cell state, but it remains a challenge t ...

Informa Healthcare2016

Pro-oxidant effects of nano-TiO2 on Chlamydomonas reinhardtii during short-term exposure

Olivier Martin, Paul Bowen, Christian Santschi, Lionel André Maurizi, Volodymyr Koman, Nadia Rachel Von Moos, Amarnath Jayaprakash

This study sheds light on the short-term dynamics of pro-oxidant processes related to the exposure of C. reinhardtii microalgae to nano-TiO2 using (a) conventional fluorescence probes for cellular pro-oxidant process and (b) a recently developed cytochrome ...

Royal Soc Chemistry2016

Multiscattering-Enhanced Absorption Spectroscopy

Christian Santschi, Olivier Martin, Volodymyr Koman

An original scheme for sensitive absorption measurements, particularly well-suited for low analyte concentrations, is presented. The technique is based on multiscattering-enhanced absorption spectroscopy (MEAS) and benefits from the advantages of conventio ...

Amer Chemical Soc2015

Portable oxidative stress sensor: Dynamic and non-invasive measurements of extracellular H2O2 released by algae

Christian Santschi, Olivier Martin, Volodymyr Koman

Reactive oxygen species (ROS) generated by aerobic organisms are essential for physiological processes such as cell signaling, apoptosis, immune defense and oxidative stress mechanisms. Unbalanced oxidant/antioxidant budgets are involved in many diseases a ...

Elsevier2015

Multiscattering-enhanced optical biosensor: multiplexed, non-invasive and continuous measurements of cellular processes

Christian Santschi, Olivier Martin, Volodymyr Koman

The continuous measurement of uptake or release of biomarkers provides invaluable information for understanding and monitoring the metabolism of cells. In this work, a multiscattering-enhanced optical biosensor for the multiplexed, non-invasive, and contin ...

Optical Soc Amer2015

Multiscattering-enhanced optical probes for biosensing

Volodymyr Koman

Although reactive oxygen species (ROS) are an inescapable part of every living organism, we are only beginning to understand their functions and mechanics. As of now, we know that ROS are involved in cell signalling, stress-response and defence against pat ...

EPFL2015

Measuring the optical absorption of 10 nm gold nanoparticles using multiscattering-enhanced absorption spectroscopy in a dielectric metamaterials

Christian Santschi, Olivier Martin, Volodymyr Koman

2014

A portable microfluidic-based biophotonic sensor for extracellular H2O2 measurements

Jürgen Brugger, Olivier Martin, Christian Santschi, Victor Javier Cadarso Busto, Guillaume Suarez, Volodymyr Koman, Nadia Rachel Von Moos

2013