Electrochemistry of Biosystems
Linking Glucose Oxidation to Luminol-based Electrochemiluminescence using bipolar Electrochemistry
Asymmetric Modification of TiO2 Nanofibers with Gold by Electric-Field-Assisted Photochemistry
Stimuli-responsive microgels for electrochemiluminescence amplification

Ruigrok, H.J., Arnaud-Cormos D., Hurtier A., Poque-Haro E., Poulletier de Gannes F., Ruffié G., Bonnaudin F, Lagroye I., Sojic N., Arbault S., Lévêque P., Veyret B. and Percherancier Y.

Radiation Research, 2018, 189 (1), 95-103

The existence of effects of radiofrequency field exposure at environmental levels on living tissues and organisms remains controversial, in particular regarding potential ‘‘nonthermal’’ effects produced in the absence of temperature elevation. Therefore, we investigated whether TRPV1, one of the most studied thermosensitive channels, can be activated by the heat produced by radiofrequency fields and by some specific nonthermal interaction with the fields. We have recently shown that TRPV1 activation can be assessed in real-time on live cells using the bioluminescence resonance energy transfer technique. Taking advantage of this innovative assay, we monitored TRPV1 thermal and chemical modes of activation under radiofrequency exposure at 1800 MHz using different signals (CW, GSM, UMTS, LTE, Wi-Fi and WiMAX) at specific absorption rates between 8 and 32 W/kg. We showed that, as expected, TRPV1 channels were activated by the heat produced by radiofrequency field exposure of transiently-transfected HEK293T cells, but found no evidence of TRPV1 activation in the absence of temperature elevation under radiofrequency field exposure. There was no evidence either that, at fixed temperature, radiofrequency exposure altered the maximal efficacy of the agonist Capsaicin to activate TRPV1.

2018 07

Girard F., Peret M., Dumont N., Badets V., Blanc S., Gazeli K., Noël C., Belmonte T., Marlin L., Cambus J.P., Simon G., Sojic N., Held B., Clément F. and Arbault S.

Phys. Chem. Chem. Phys., 2018, 20, 9198-9210

The understanding of plasma-liquid interactions is of major importance, not only in physical chemistry, chemical engineering and polymer science, but in biomedicine as well as to better control the biological processes induced on/in biological samples by Cold Atmospheric Plasmas (CAPs). Moreover, plasma-air interactions have to be particularly considered since these CAPs propagate in the ambient air. Herein, we developed a helium-based CAP setup equipped with a shielding-gas device, which allows the control of plasma-air interactions. Thanks to this device, we obtained specific diffuse CAPs, with the ability to propagate along several centimetres in the ambient air at atmospheric pressure. Optical Emission Spectroscopy (OES) measurements were performed on these CAPs during their interaction with a liquid medium (Phosphate-Buffered Saline PBS 10 mM, pH 7.4) giving valuable information about the induced chemistry as a function of the shielding gas composition (variable O2/(O2+N2) ratio). Several excited species were detected including N2+(First Negative System, FNS), N2(Second Positive System, SPS) and HO· radical. The ratios between nitrogen/oxygen excited species strongly depend on the O2/(O2+N2) ratio. The liquid chemistry developed after CAP treatment was investigated by combining electrochemical and UV-visible absorption spectroscopy methods. We detected and quantified stable oxygen and nitrogen species (H2O2, NO2-, NO3-) along with Reactive Nitrogen Species (RNS) such as the peroxynitrite anion ONOO-. It appears that the RNS/ROS (Reactive Oxygen Species) ratio in the treated liquid depends also on the shielding gas composition. Eventually, the composition of the surrounding environment of CAPs seems to be crucial for the induced plasma chemistry and consequently, for the liquid chemistry. All these results demonstrate clearly that for physical, chemical and biomedical applications, which are usually achieved in ambient air environments, it is necessary to realize an effective control of plasma-air interactions.

2018 08

L. Bouffier, N. Sojic, A. Kuhn

Current Opinion in Electrochemistry 2018, 7:A1–A4

This section of Current Opinion in Electrochemistry includes 17 articles contributed by groups from all over the world and we hope they will give the reader a representative vision of the latest achievements in the different areas of research. All selected authors are very active in frontier studies on physical and nanoelectrochemistry.

Girard F., Peret M., Dumont N., Badets V., Blanc S., Gazeli K., Noël C., Belmonte T., Marlin L., Cambus J.P., Simon G., Sojic N., Held B., Clément F. and Arbault S.

Integrative Biology, 2018, in press

Phospholipid Giant Unilamellar Vesicles (GUVs) are usually prepared by electroformation in water, that is in a low-conductivity solution. We developed a protocol allowing their electroformation in the most common physiological buffer, the phosphate-buffered saline (PBS). This was achieved based on a specific sequence of increasing electrical fields and for the two usual electrode types for electroformation, namely Indium Tin Oxide-coated glass slides and Pt electrodes. These GUVs are stable over time (hour time-scale) and they can be isolated or micro-injected. The membrane composition was modified by adding cholesterol in order to adjust its mechanical properties. The optimal proportion of cholesterol vs. total phospholipid concentration was 20 mol % ratio which increases membrane rigidity and facilitates vesicle microinjection.

2018 09

E. Suraniti, A.G. Mark, J. Roche, H. Richter, A. Kuhn, P. Fischer, N. Mano

L’Actualité Chimique 2018, 427-428,127-128

Une micro-source d’énergie intégrée permettrait à des implants biomédicaux miniatures de fonctionner de façon autonome. Les piles ou batteries conventionnelles sont peu adaptées à cette utilisation car difficiles à miniaturiser. Des biopiles enzymatiques peuvent produire l’énergie in situ par la transformation électrochimique de glucose et d’oxygène. Une micro-biopile intégrée peut donc alimenter un microcircuit électronique pour des applications biomédicales.

2018 05

Zeste de Science du CNRS


jeudi 15 février 2018
Après son communiqué de presse paru en octobre dernier, le CNRS vient de mettre en ligne une vidéo de vulgarisation pour expliquer le principe de l'électrochimie bipolaire appliquée à la mise en mouvement de polymères conducteurs. Vous pouvez la consulter en cliquant sur l'image ci-dessous !

Communiqué de presse du CNRS - Des plastiques qui dansent


mercredi 11 octobre 2017
De nouveaux types d’actionneurs à base de polymères conducteurs ont été publiés dans la revue Angewandte Chemie et viennent de faire l'objet d'un communiqué de presse du CNRS. L’originalité de l'approche réside dans le déclenchement d'une déformation réversible d’un plastique à distance par voie électrochimique. Ce processus, qui exploite le principe de l'électrochimie bipolaire, se déroule sans aucune connexion physique et permet d’actionner plusieurs objets... Read More...

Communiqué de presse du CNRS - Semi-conducteurs Janus


lundi 24 juillet 2017
Dans le cadre d'une collaboration avec des scientifiques thaïlandais (centre VISTEC à Rayong et Kasetsart University à Bangkok), notre équipe vient de mettre au point un nouveau procédé permettant de synthétiser des particules "Janus" semi-conductrices qui pourraient trouver application dans le domaine de la catalyse, et notamment celui de la photolyse de l’eau. Les résultats de ces travaux ont été publiés dans la revue Angewandte Chemie et viennent de faire l'objet d'un... Read More...

Financement ERC pour Alexander Kuhn


mercredi 3 mai 2017
Alexander KUHN vient d'obtenir un financement de l'ERC pour une durée de 5 ans ! L'objectif global du projet, intitulé ELECTRA, est de proposer des stratégies jusqu'à présent inexplorées et polyvalentes, basées sur l'utilisation non-conventionnelle de phénomènes électrochimiques, pour générer une asymétrie dans des systèmes chimiques à différentes échelles de longueur.... Read More...

Distinguished Fellow


lundi 11 janvier 2016
The French Chemical Society has selected Alexander Kuhn as one of its new distinguished fellows. The official ceremony will be held in May 2016 in Paris. Congratulations!