Structure, electrochemical properties and functionalization of amorphous CN films deposited by femtosecond pulsed laser ablation

Amorphous carbon nitride (a-C:N) material has attracted much attention in research and development. Recently, it has become a more promising electrode material than conventional carbon based electrodes in electrochemical and biosensor applications. Nitrogen containing amorphous carbon (a-C:N) thin films have been synthesized by femtosecond pulsed laser deposition (fs-PLD) coupled with plasma assistance through Direct Current (DC) bias power supply. During the deposition process, various nitrogen pressures (0 to 10 Pa) and DC bias (0 to ¿ 350 V) were used in order to explore a wide range of nitrogen content into the films. The structure and chemical composition of the films have been studied by using Raman spectroscopy, electron energy-loss spectroscopy (EELS) and high-resolution transmission electron microscopy (HRTEM). Increasing the nitrogen pressure or adding a DC bias induced an increase of the N content, up to 21 at.%. Nitrogen content increase induces a higher sp2 character of the film. However DC bias has been found to increase the film structural disorder, which was detrimental to the electrochemical properties. Indeed the electrochemical measurements, investigated by cyclic voltammetry (CV), demonstrated that a-C:N film with moderate nitrogen content (10 at.%) exhibited the best behavior, in terms of reversibility and electron transfer kinetics. Electrochemical grafting from diazonium salts was successfully achieved on this film, with a surface coverage of covalently bonded molecules close to the dense packed monolayer of ferrocene molecules. Such a film may be a promising electrode material in electrochemical detection of electroactive pollutants on bare film, and of biopathogen molecules after surface grafting of the specific affinity receptor.This work is produced with the financial support of the Future Program Lyon Saint-Etienne (PALSE) from the University of Lyon (ANR-11-IDEX-0007), under the “Investissements d'Avenir” program managed by the National Agency Research (ANR)

A Collaborative Filtering Approach for Protein-Protein Docking Scoring Functions

A protein-protein docking procedure traditionally consists in two successive tasks: a search algorithm generates a large number of candidate conformations mimicking the complex existing in vivo between two proteins, and a scoring function is used to rank them in order to extract a native-like one. We have already shown that using Voronoi constructions and a well chosen set of parameters, an accurate scoring function could be designed and optimized. However to be able to perform large-scale in silico exploration of the interactome, a near-native solution has to be found in the ten best-ranked solutions. This cannot yet be guaranteed by any of the existing scoring functions

Accute parameter optimization leads to predictive dynamical models for systems biology

International audienc

Accurate parameter optimization leads to predictive dynamical models for systems biology

International audienc

Laser technologies for the development of carbon materials on flexible substrates for environmental analytical microsystems

International audienc

Structural and electrochemical properties of amorphous carbon nitride films deposited by femtosecond pulsed laser ablation

International audienceAmorphous carbon nitride (a-C:N) material has attracted much attention in research and development [1]. Recently, it has become a more promising electrode material than conventional carbon based electrodes in electrochemical and biosensor applications [2]. Nitrogen containing amorphous carbon (a-C:N) thin films have been deposited by femtosecond pulsed laser deposition (fs-PLD) coupled with plasma assistance. During the deposition process, various nitrogen pressures (0-50 Pa) and Direct Current (DC: 0-400 V) biases were used in order to introduce a wide range of nitrogen content into the films. The ablated carbon plume expansion has been investigated by ICCD gated Optical emission spectroscopy (OES) and direct 2D spectral imaging under N2 gas and DC plasma assistance. The structure and chemical composition of the films have been studied by using Multi-wavelength (MW) Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Electron energy loss spectroscopy (EELS) and Reflection electron energy loss spectroscopy (REELS). While deposition, the intensity of the reactive activated species in the plasma plume is increased with DC biased assistance as compared to the bare N2 atmosphere, which was confirmed by optical emission spectroscopy, those deposition conditions induce an overall increase of nitrogen content in films up to 28 at.% and the formation of sp2 rich graphitic-like structures. Electrochemical properties have been investigated by cyclic voltammetry (CV) measurements to choose innovative electrode material for sensor applications. The a-C:N films show better electron transfer kinetics and excellent reproducibility than the pure a-C films. This study reveals the a-C:N films could be a promising electrode material in electrochemical detection of traces of pollutants and bio pathogen molecules. It is expected to be an alternative to BDD electrode in the near futur

Technology transfer from laboratory to industry for fabrication of large superconducting coil joints

The future magnetic thermonuclear fusion reactors will use superconducting magnets. The development during the last decade of the cable-in-conduit conductor (CICC) allows the transport of high current intensities. The construction of the winding pac