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Au nanoparticles functionalized by short poly(ethylene glycol) chain ligands were suspended in a hydroalcoholic medium. This suspension was then printed by inkjet onto a Kapton® substrate. Gold electrodes consisting of four stacked printed layers exhibited a conductivity of (1 ± 0.1) × 107 S/m, close to that of Au bulk, after low-temperature thermal annealing. The electrochemical behaviour with respect to heterogeneous electron transfer reactions and the reactivity towards thiol chemisorption are identical to those obtained when a conventional polycrystalline Au electrode is used.

This review first recalls the basic functioning principles of organic electrochemical transistors (OECTs) then focuses on the transduction mechanisms applicable to OECTs. Materials constituting the active semiconducting part are reviewed, from the historical conducting polymers (polyaniline, polypyrrole) to the actual gold standard, poly-3,4-ethylenedioxythiophene: polystyrene sulfonic acid (PEDOT:PSS), as well as the methods used to fabricate these transistors. The review then focuses on applications of OECTs for the detection of small molecules and more particularly of metabolites, with a distinction between enzymatic and non-enzymatic transduction pathways. Finally, the few patents registered on the topic of OECT-based biosensors are reviewed, and new tracks of improvement are proposed.

A number of serious diseases are linked to copper homeostasis dysfunction. The design of copper(I)-selective chelators is of particular interest not only for the creation of therapeutic objects but also as useful tools to gain insights into the coordination of copper(I) in a biological medium. A water-soluble Cu(I)-selective ligand that associates strong Cu(I) binding at pH = 7.4 (10(14) M(-1)), insensitivity to air, and selectivity toward Cu(II) and other biologically relevant cations is described.

Small Molecule Activation; International audience; Reduction of CO2 is a fruitful approach for storage of renewable electric energy as well as for the production of value added chemicals. Using variously substituted iron tetraphenylporphyrins and iron and cobalt macrocyclic pentadendate N5 complexes electrochemically or photochemically reduced to their active states, selective and efficient molecular catalysis of the CO2-to-CO and of the CO2-to-HCOOH conversion was achieved at low overpotential. From fruitful joint experimental and mechanistic studies rooted in the analysis of cyclic voltammograms, the mechanisms for catalysis were fully deciphered, allowing not only to give a complete picture of the catalytic processes but also to identify the main parameters for optimizing the catalyst structure. Efficient CO2 catalysis was performed not only in aprotic but also in aqueous conditions, opening the way to the design of electrochemical or photo-electrochemical cells, a key step for future applied devices.

The covalent grafting of an Fe porphyrin on carbon nanotubes led to efficient electroreduction of CO

We report the synthesis of a bis(urea) gelator designed to specifically mimic the chemical structure of the highly polymorphic drug substance ROY. Crystallization of ROY from toluene gels of this gelator results in the formation of the metastable red form instead of the thermodynamic yellow polymorph. In contrast, all other gels and solution control experiments give the yellow form. Conformational and crystal structure prediction methods have been used to propose the structure of the gel and show that the templation of the red form by the targeted gel results from conformational matching of the gelator to the ROY substrate coupled with overgrowth of ROY onto the local periodic structure of the gel fibres., Engineering and Physical Sciences Research Council EP/J013021/1

International audience; The electrochemical and photochemical catalytic reductions of CO2 using N,O and N,S-NHC-containing dicarbonyl rhenium(I) bipyridine complexes have been investigated. By replacing the carbonyl ligand in tricarbonyl rhenium(I) complexes with a weaker π-accepting ligand, the characteristic MLCT transitions shifted to lower energy. This makes photocatalysts capable of harvesting low-energy visible light for catalyzing CO2 reduction. A detailed study revealed that these dicarbonyl rhenium(I) complexes are also highly selective for photocatalysis of CO2 to CO with a good quantum efficiency (10%), similar to that of the tricarbonyl rhenium(I) complex analogues. From the electrochemical study, it was observed that the catalysts efficiently produce CO from CO2 with high turnover frequency and good stability over time.

International audience; Catalysis of fuel-producing reactions can be transferred from homogeneous solution to surface via attachment of the molecular catalyst. A pyrene-appended iron triphenyl porphyrin bearing six pendant OH groups on the phenyl rings in all ortho and ortho′ positions was immobilized on carbon nanotubes via noncovalent interactions and further deposited on glassy carbon. X-ray photoelectron spectroscopy and electrochemistry confirm catalyst immobilization. Using the carbon material, highly selective and rapid catalysis of the reduction of CO2 into CO occurs in water (pH 7.3) with 480 mV overpotential. Catalysis could be sustained for hours without loss of activity and selectivity, and high turnover number was obtained.