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Purpose: Managing hip fracture surgery in patients taking clopidogrel is challenging. The optimal timing for surgery remains unclear. Early surgery in such patients potentially increases peri-operative bleeding, whereas delayed surgery has been shown to be associated with worse postoperative outcomes. The aim of this study was to investigate whether a delay to surgery affects total blood loss, bleeding kinetics, blood transfusion requirements, or post-operative outcomes.Methods: A retrospective monocentric study including all hip fracture patients treated with clopidogrel between 2011 and 2016 (39 patients) was carried out. Patients who underwent delayed surgery after withholding clopidogrel for five days or more, from 2011 to 2013, were compared to patients who benefited from earlier surgical procedures (within 48 hours of admission) from 2014 to 2016.Results: Total blood loss, amount of blood transfusion and rate of postoperative complications did not differ between the two groups. However, the timing of bleeding was significantly different; blood loss occurred during the pre-operative phase in the delayed surgery group (p < 0.0001), whereas it occurred during the intra-operative phase in the early surgery group (p = 0.005). The length of the hospital stay was significantly shorter for the early surgery group than for the delayed surgery group: 11 ± three versus 15 ± four days (p = 0.004).Conclusions: Early surgical treatment of hip fracture in patients receiving clopidogrel does not increase the overall red blood cell loss or the transfusion requirement, but may affect the timing of blood transfusion. Hip fracture surgery should preferably be performed without delay in patients taking clopidogrel. [ABSTRACT FROM AUTHOR]

Introduction The prediction of fluid responsiveness in paediatrics and infants remains problematic. We sought to test the validity of the measurement of StcO 2 as a predictive parameter of fluid responsiveness in infants less than one year old during non-cardiac surgery. Materials and methods This was a prospective observational study on infants aged less than 1 year without any cardiac disease during the intraoperative period of non-cardiac surgery. Cerebral oxygen saturation (StcO 2 ) was obtained using infrared spectroscopic INVOS ® monitors. Reference values were obtained 10 minutes after intubation. Fluid load indications were dependent on the anaesthesiologist caring for the patient. The objective of this study was to determine the accuracy of StcO 2 values before vascular filling (StcO 2 B) and the difference in StcO 2 values between the reference value and before vascular filling (ΔStcO 2 ), in predicting vascular filling response defined as an increase in mean arterial pressure over 15%. Statistical analysis was carried out using ROC curve analysis with determination of grey zones. Results Twenty-nine patients were eligible for this study, 23 were included in the study (one intravenous fluid challenge per patient). There were 10 responders and 13 non-responders. The StcO 2 B and the ΔStcO 2 were significantly different between responders and non-responders. Analysis of the ROC curve found an area under the curve of 0.75 [95% CI 0.56 to 0.95] for StcO 2 B and 0.83 [95% CI 0.66 to 0.99] for ΔStcO 2 . The grey-areas were [59–78] and [16–28] for StcO 2 B and ΔStcO 2 . Conclusion NIRS appears to be an interesting additional tool for predicting an increase of blood pressure in response to intraoperative fluid challenge in infants less than one year old. [ABSTRACT FROM AUTHOR]

A ferrocene-conjugated nonapeptide composed of alternating d- and l-residues and containing two sulfide linkages was synthesized (LCys-DPhe-LPhe-DPhe-(Ferrocene)LLys-DAla-LAsp-DAla-LCys-NH2) as novel material for nanostructure formation. The cyclic nonapeptide assembly onto gold was highly disordered and included a large dead volume on the gold surface. Also, a large proportion of ferrocene units (79%) were located in microenvironments where electron transfer was hindered. On the other hand, two kinds of self-assembled nanostructure morphologies: linear and ring were observed on mica, depending on the age of the peptide solution used in the adsorption process. Linear nanostructures, 100–1000 nm in length and 1.4–4.0 nm in height, were observed by AFM when using freshly prepared peptide solutions. Rings, 100–200 nm in diameter and 1.6 nm in height, were obtained when using a 2-month aged peptide solution. [ABSTRACT FROM AUTHOR]

Even though their occurrence was reported a long time ago, sunken wood ecosystems at the deep-sea floor have only recently received specific attention. Accumulations of wood fragments in the deep sea create niches for a diverse fauna, but the significance of the wood itself as a food source remains to be evaluated. Pectinodonta sp. is a patellogastropod that exclusively occurs on woody substrates, where individuals excavate deep depressions, and is thus a potential candidate for a wood-eating lifestyle. Several approaches were used on Pectinodonta sampled close to Tongoa island (Vanuatu) to investigate its dietary habits. Host carbon is most likely derived from the wood material based on stable isotopes analyses, and high cellulase activity was measured in the digestive mass. Electron microscopy and FISH revealed the occurrence of two distinct and dense bacterial communities, in the digestive gland and on the gill. Gland-associated 16S rRNA gene bacterial phylotypes, confirmed by in situ hybridization, included members of three divisions ( Alpha- and Gammaproteobacteria, Bacteroidetes), and were moderately related (90-96% sequence identity) to polymer-degrading and denitrifying bacteria. Gill-associated phylotypes included representatives of the Delta- and Epsilonproteobacteria. The possible involvement of these two bacterial communities in wood utilization by Pectinodonta sp. is discussed. [ABSTRACT FROM AUTHOR]

Abstract: We studied biofilm formation on stainless steel occurring in a drinking water distribution system which operated in parallel at 20 and 37°C, in order to focus on the effect of temperature rather than on other operational and water quality parameters. A surface conditioning step was followed as a function of time on this material until adhesion of bacterial colonies by using microscopic methods: scanning electron microscopy (SEM) and atomic force microscopy (AFM); a spectroscopic method: polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), and an electrochemical method: rotating disk electrode (RDE). Correlations between surface analysis, the duration of immersion of the sample and the influence of temperature have been identified clearly before bacterial adhesion. In cold water, these results showed an initial conditioning step of surface occurring during the first 8days, with detection of superficial acidic functions grafted on surface, until adsorption of proteins. After 12days, formation of independent bacteria microcolonies, reaching 2–3μm in length was observed. In tepid water, the first step was reduced to 2days during which carbonates, acidic functions, and proteins were detected. After 90days, the biofilm entered in a stable population state, which appeared as a bacteria rich film, including possibly Legionella. The spatial variation of the biofilm was limited as deduced from the thickness determination (about 4μm for 3-month period), using a RDE. The combination of these different techniques confirms successive steps for biofilm formation on stainless steel in a tap water. Then, we scrutinized the external near environment of bacteria including extracellular polymeric substances (EPS) and then further characterize the morphology of dominant bacteria (shape, size, flagellum) on gold substrate by AFM in air. [Copyright &y& Elsevier]

Abstract: Sunken woods are abundant in deep oceanic environments, housing a huge faunal diversity. Studies on that substrate firstly focused on the associated organisms, but since a few years, identification of wood is a further aim. The purpose is to appreciate its degradation state, diversity, geographical origin and to identify specific associations between colonizing organisms and substrates. The first determinations were made on sunken woods from Taiwan/Philippines, the Vanuatu Archipelago, and the Mediterranean Sea. Samples’ identification was based on histological studies. Different preparation techniques were used, depending on their degradation state. Detailed anatomy descriptions were made and compared to the native flora and the introduced species. Wood samples were well preserved. Diversified species were encountered, seemingly originating from local floras. In situ settlements of known wood species will enhance the knowledge of degradation and colonization degrees. [Copyright &y& Elsevier]

Abstract  Composite materials based on iron-oxide nanoparticles (magnetite, hematite, and maghemite) and tetraoxalate-doped polypyrrole (PPy) were electrochemically generated from aqueous solutions. Their composition was determined using electrochemical quartz crystal microbalance experiments. The oxide percentage in mass was found to vary from 17 to 27% depending on the oxide identity. They were all shown to be fascinating candidates as protective materials against corrosion of iron and carbon steel materials although maghemite-nanoparticle-loaded polypyrrole films offer the best performances. An anionic surfactant (sodium dodecylsulfate) was added to the electrodeposition solution to avoid the formation of clusters. These anions were also shown to improve the conductivity of the resulting PPy films, while the presence of oxide nanoparticles tends to decrease this same surface conductivity. On the other hand, the correlation between the morphology and the local conductivity appears to be more obvious in the absence of anionic surfactants than in their presence. This aspect is discussed although it still needs further investigation. [ABSTRACT FROM AUTHOR]

Two trawl samples of natural sunken wood collected near Vanuatu were identified based on histological studies. Detailed descriptions were made and microphotographs of the cell types were taken, using the three classical sections (cross, tangential and radial). The botanical characters were compared first to the native flora of Vanuatu, then also to the introduced species. The possibility of transportation by ocean currents with a mainly southern and eastern direction is discussed. The first sample lacks apparent colonization marks. Its main histologic character is the presence of ‘paedomorphic type I rays’ which relates it to the shrubby genera Fitchia (Asteraceae) and Fuchsia (Onagraceae): both are known in Polynesia but they seem not to be recorded from Vanuatu. The second wood sample is densely colonized by molluscs and other fauna. It comes from a tree close to the Fabaceae-Mimosoideae, possibly belonging to the genera Leucaena or Serianthes, both known from Vanuatu. Our work shows for the first time that, even after prolonged submergence in water at substantial depth (>500 m), the wood structure may be well preserved. Therefore, the botanical identification and the determination of the origin of the sunken wood were possible. The two selected samples show completely different colonization patterns, which could be related to differences in chemical composition or to time elapsed since sinking. [ABSTRACT FROM AUTHOR]

In a preliminary study aimed at developing strategies for the simultaneous detection of various biologically important molecules, a procedure is described that allows the electrochemical detection of nitric oxide (NO) released by a population of human umbilical vein endothelial cells (HUVEC) by using an array of electrodes comprising three individually addressable electrodes. Each electrode in the array was modified with a different NO-sensitive electrocatalyst, thereby demonstrating the possibility of modifying the individual electrodes in an array with different sensing chemistries. This study opens a doorway to the development of arrays of electrodes for the simultaneous detection of multiple analytes in a complex environment by suitably tailoring the sensitivity and selectivity of each electrode in the array to a specific analyte in the test medium. [ABSTRACT FROM AUTHOR]

Pt microelectrodes (50 μm diameter) were positioned by means of scanning electrochemical microscopy assisted z-approach curves and in situ modified with nickel tetrasulfonated phthalocyanine tetrasodium salt as electrocatalytic layer for the specific oxidative detection of nitric oxide. The thus modified electrodes were then moved over a layer of adherently growing human umbilical vein endothelial cells (HUVEC) in order to amperometrically detect nitric oxide (NO) released from the cells upon stimulation with bradykinin. This approach actually takes advantage of the use of SECM to define a sequential procedure that enables the in situ functionalisation of the SECM tip thus allowing to accurately control the separation between the functionalised SECM tip and the cell population. [Copyright &y& Elsevier]

We report here on the appropriate analysis of some examples of interfering compounds that should be done to assess the specificity of the electrochemical sensing of nitric oxide in solution. To do so, we describe the design of a nickel porphyrin and Nafion®-coated carbon microfibre and discuss the methodological approach in examining interfering compounds. [Copyright &y& Elsevier]

A preliminary evaluation of the electrochemical behaviour of phenolic calix[n]arenes (n=4,6) possessing either H- or tert-butyl functionality at the para-phenol position has been undertaken by cyclic voltammetry. Electrochemical activity of these calixarenes is an inherent property, due to oxidation of the phenolic moiety in both types of calixarene. Oxidation of the p-H-substituted calixarenes leads to an electrode passivation process whereas oxidation of the p-t-butyl-substituted calixarenes does not. The former is attributed to electropolymerisation via intermolecular reaction of calixarene phenoxy radical species at the para-position to produce a non-conducting deposit on the electrode surface. This process is not possible with the p-t-butyl-substituted calixarenes. [Copyright &y& Elsevier]

Nitrogen rich carbon nitride (CNx) materials were prepared using reactive magnetron sputtering from a pure nitrogen plasma at elevated deposition pressures and low deposition powers. Solid-state photovoltaic devices utilizing such materials were prepared and characterized. As-prepared CNx materials showed photoconductive behaviour and no photovoltaic effect. This was attributed to the p-doping effect of oxygen present in as-prepared CNx films resulting in formation of a compensated semiconductor. However, upon thermal annealing, CNx materials showed a pronounced photovoltaic effect consistent with the n-type semiconductor behaviour. This result demonstrates that nitrogen rich carbon nitride is a promising photovoltaic material for all-carbon photovoltaic solar cells. [ABSTRACT FROM AUTHOR]

The model suggested by Deslouis and co-workers [14] for describing the behavior of polypyrrole deposited on a metallic substrate is here used for conducting polymers deposited on a nanostructured 3D semiconducting substrate. Impedance measurements were performed on a titanium oxide nanotubular array in the presence of two types of conducting polymers: polypyrrole and poly(3,4-ethylenedioxythiophene), highlighting the modification of the semiconducting properties of the substrate induced by the polymer deposition. The model is shown to be particularly well adapted for the PEDOT/TiO 2 hybrid structure, providing a valuable tool for characterizing the interaction between the conducting polymer and the semiconducting substrate. [ABSTRACT FROM AUTHOR]

Abstract: Our purpose is here to produce a large area 3D junction between anatase type TiO2 and polypyrrole (PPy) in a Ti/TiO2 nanotube array (NTA)/PPy assembly with the help of electrochemical methods only. We report herein the influence of light and background salt on the electrochemical polymerization of pyrrole from aqueous electrolytic solutions on titanium oxide NTAs, a well-known large specific area n-type semiconductor substrate. As titanium dioxide is known to be poorly conducting in the anodic potential range, we confirmed that light is able to initiate a polymerization process of pyrrole, at a moderately high anodic potential. For comparison with results obtained in sodium dodecylbenzenesulfonate (SDBS) at micellar concentration, we used here also lithium perchlorate as background salt at a 0.1M concentration, and PPy growth was found to be faster in the presence of LiClO4. Moreover in the latter case polypyrrole could be initiated in the dark as well, yet at an enhanced deposition rate under UV light. In the two solutions. the resulting polypyrrole films were found to be electroactive, i.e. able to undergo electrochemically driven doping/undoping processes, yet with a higher electroactivity for the film obtained in LiClO4. SEM-FEG and Raman spectroscopy experiments confirmed respectively that i) the initial steps of the photo-assisted electrodeposition of polypyrrole films occur first at the mouth of the titanium dioxide nanotubes, before leading to the well-known cauliflower-like morphology for PPy and ii) PPy is systematically produced in a doped state. [Copyright &y& Elsevier]

Abstract: Electrogenerated polypyrrole films doped with hexasulfonated calix[6]arenes were subjected to ac-electrogravimetry and electrochemical atomic force microscopy (EC-AFM) studies in aqueous potassium nitrate solutions. The former technique reveals that these films are mainly cation exchangers although solvent molecules (H2O) and anions (NO3 −) are also exchanged, in much lower amounts, in the course of the doping/undoping process. Unexpectedly, within the potential range encompassing this process, K+ cations were found to be exchanged for more cathodic potentials whereas H3O+ are exchanged for more anodic potentials. EC-AFM investigations revealed substantial shrinking and swelling during the oxidation (doping) and reduction (undoping) processes respectively. An obvious correlation can easily be built between these observations: the oxidation of the polymer films provokes an expulsion of the cations, as expected from cation exchanger polymer films, and therefore a decrease of the volume (and thickness) of these films whereas their reduction causes an insertion of cations and an increase of their volume (and thickness). This electromechanical mechanism is amplified by the simultaneous exchange of free water molecules. Suggestions based on these observations, on structural characteristics of polypyrrole films, and on complexation ability of hexasulfonated calix[6]arenes incorporated in the films are discussed to explain (i) the change of the identity of the exchanged cations as a function of the potential, (ii) the exchange of free water molecules and, (iii) the exchange of small amounts of nitrate ions. [Copyright &y& Elsevier]

Abstract: In this study, our goal was to test whether typical vent/seep organisms harbouring symbionts or not, would be able to settle on organic substrates deployed in the vicinity of chemosynthetic ecosystems. Since 2006, a series of novel standardized colonization devices (CHEMECOLI: CHEMosynthetic Ecosystem COlonization by Larval Invertebrates) filled with three types of substrates (wood, alfalfa and carbonate) have been deployed in different types of reducing habitats including cold seeps in the eastern Mediterranean, a mud volcano in the Norwegian Sea, and hydrothermal vents on the Mid-Atlantic Ridge for durations of 2 weeks to 1 year. For all deployments, highest species diversities were recovered from CHEMECOLIs filled with organic substrates. Larvae from species associated with thiotrophic symbionts such as thyasirid, vesicomyid and mytilid bivalves, were recovered in the eastern Mediterranean and at the Mid-Atlantic Ridge. At the Haakon Mosby Mud Volcano, larvae of symbiotic siboglinids settled on both organic and carbonate substrates. Overall, novel colonization devices (CHEMECOLI) filled with organic substrates attracted both fauna relying on chemosynthesis-derived carbon as well as fauna relying on heterotrophy the latter being opportunistic and tolerant to sulphide. [Copyright &y& Elsevier]

With an increased appreciation of the frequency of their occurrence, large organic falls such as sunken wood and whale carcasses have become important to consider in the ecology of the oceans. Organic-rich deep-sea falls may play a major role in the dispersal and evolution of chemoautotrophic communities at the ocean floor, and chemosynthetic symbiotic, free-living, and attached microorganisms may drive the primary production at these communities. However, little is known about the microbiota thriving in and around organic falls. Our aim was to investigate and compare free-living and attached communities of bacteria and archaea from artificially immersed and naturally sunken wood logs with varying characteristics at several sites in the deep sea and in shallow water to address basic questions on the microbial ecology of sunken wood. Multivariate indirect ordination analyses of capillary electrophoresis single-stranded conformation polymorphisms (CE-SSCP) fingerprinting profiles demonstrated high similarity of bacterial and archaeal assemblages present in timbers and logs situated at geographically distant sites and at different depths of immersion. This similarity implies that wood falls harbor a specialized microbiota as observed in other ecosystems when the same environmental conditions reoccur. Scanning and transmission electron microscopy observations combined with multivariate direct gradient analysis of Bacteria CE-SSCP profiles demonstrate that type of wood (hard vs. softwood), and time of immersion are important in structuring sunken wood bacterial communities. Archaeal populations were present only in samples with substantial signs of decay, which were also more similar in their bacterial assemblages, providing indirect evidence of temporal succession in the microbial communities that develop in and around wood falls. [ABSTRACT FROM AUTHOR]

Abstract: Erosion–corrosion is a complex materials degradation mechanism involving the combined effects of mechanical erosion and electrochemical corrosion. It is known to be induced by high shear stresses in strong flows. One way to mitigate this phenomenon is to use additives reducing the turbulent Reynolds stresses. Oleyltrimethyl ammonium cationic surfactant and sodium salicylate as counter-ion known to form thread-like micelles behaving as drag reducers were tested in this work and successfully imaged by using AFM technique. A shear stress mapping in the rotating cage using an electrochemical method was implemented in the absence and in the presence of surfactant, showing drag reduction amounts up to 65%. In a second step, erosion corrosion of Cu in Na2SO4 0.1M in the presence of small amounts of NaCl (1mM) was investigated on Cu microelectrodes located at different positions on plastic coupons in the cage. The surfactant effect was found to be beneficial by preventing the removal of the pre-existing oxide films, otherwise observed in the absence of surfactant. Tests performed with benzotriazole known as a good corrosion inhibitor for Cu, could not prevent either the breaking of the oxide film in strong flow conditions. [Copyright &y& Elsevier]

Abstract: Duplex polypyrrole (PPy) films have been electrochemically synthesized on iron to be used as protective coatings against corrosion. The inner film was doped with tetraoxalate anions and the outer one with dodecyl sulfate anions. The protection against corrosion of this coating was tested in sodium chloride solutions: an increase in the protection time by one order of magnitude with respect to an oxalate-doped PPy film of the same total thickness was measured. The proposed mechanism was based on a change in the permselectivity of the film from anion exchange to cation exchange, thus preventing from the ingress of corrosive chloride anions. [Copyright &y& Elsevier]

Thickness variations of poly(3,4-ethylenedioxythiophene) (PEDOT) thin films placed under potential conditioning were measured with the help of electrochemical atomic force microscopy (EC-AFM). In this purpose, in-situ AFM operating in the contact mode was coupled with either cyclic voltammetry (CV) or advanced cyclic voltammetry (AdCV). A PEDOT functionnalized platinum electrode was used simultaneously as a sample for in-situ AFM measurements and a working electrode in a usual three electrode electrochemical setup. PEDOT films were electrodeposited with the help of the CV technique from lithium perchlorate aqueous solutions. From these EC-AFM investigations, brand new PEDOT films were found to be anion exchangers, in good agreement with conclusions of investigations reported in literature. Unexpectedly, PEDOT films having undergone a comprehensive electrochemical cycling (i.e. an electrochemical aging) in a potential range encompassing narrowly their redox process by using tens of CV or AdCV potential cycles behave as cation exchangers. Such observation strongly suggests that the electrochemo-mechanical and ion exchange behaviours of PEDOT can be both switched by simply using a potential cycling. Interestingly, the initial steps of this switching process were observed on a brand new PEDOT film during 26 consecutive CV scans. In the course of this process still ongoing at the end of the 26th cycle, a second swelling peak appears and grows progressively beside the initial swelling peak attributed to an anion exchange behaviour. This leads to a dual ion exchange behaviour for the resulting PEDOT film within the explored potential range. Indeed, this new swelling peak can be attributed to a cation exchange behaviour from the comparison of the potential dependant chronothicknograms and corresponding voltathicknograms with those obtained previously in this work. [ABSTRACT FROM AUTHOR]

Alpha 2 -macroglobulin (α 2 M) is a physiological macromolecule that facilitates the clearance of many proteinases, cytokines and growth factors in human. Here, we explored the effect of induced forms of α 2 M on anticoagulant drugs. Gla-domainless factor Xa (GDFXa) and methylamine (MA)-induced α 2 M were prepared and characterized by electrophoresis, immunonephelometry, chromogenic, clot waveform and rotational thromboelastometry assays. Samples from healthy volunteers and anticoagulated patients were included. In vivo neutralization of anticoagulants was evaluated in C57Bl/6JRj mouse bleeding-model. Anticoagulant binding sites on induced α 2 M were depicted by computer-aided energy minimization modeling. GDFXa-induced α 2 M neutralized dabigatran and heparins in plasma and whole blood. In mice, a single IV dose of GDFXa-induced α 2 M following anticoagulant administration significantly reduced blood loss and bleeding time. Being far easier to prepare, we investigated the efficacy of MA-induced α 2 M. It neutralized rivaroxaban, apixaban, dabigatran and heparins in spiked samples in a concentration-dependent manner and in samples from treated patients. Molecular docking analysis evidenced the ability of MA-induced α 2 M to bind non-covalently these compounds via some deeply buried binding sites. Induced forms of α 2 M have the potential to neutralize direct oral anticoagulants and heparins, and might be developed as a universal antidote in case of major bleeding or urgent surgery. [ABSTRACT FROM AUTHOR]

Mesoporous silica SBA-15 was functionalized with various amines and then doped with copper II cation (Cu2+). The modified materials were tested for the retention of CO 2 at room temperature using temperature-programmed desorption (CO 2 -TPD). Several parameters affecting the CO 2 retention capacity (CRC) such as the nature of amine groups, repetitive adsorption-desorption cycles and dispersion of copper were investigated. CO 2 -TPD and H 2 O-TPD allowed correlating the hydrophilic character with the CO 2 retention capacity. The obtained results showed that amine-functionalized mesoporous materials containing their own moisture exhibit higher effectiveness in the retention of CO 2. Triamine-functionalized SBA-15 displayed the highest CRC value as a result of the increase of the number of adsorption sites. Material reuse in three adsorption/desorption cycles revealed high stability with a slight decrease in CRC. The dispersion of copper induced a progressive decrease in the CRC value. The CRC decreased with increasing Cu2+ content due to competitive complexation of Cu2+ by the amino groups. Image 1 • Mesoporous silica SBA-15 was functionalized with various amines then doped with copper. • New functional SBA-15 high CO 2 retention capacity. • The effect of amines nature on CO 2 adsorptions were investigated. • Mesoporous silica provided a good reusability. [ABSTRACT FROM AUTHOR]

This work concerns the preparation and modification of mesoporous silica SBA-15 with different amine-copper complexes in order to study their impact on the catalytic behavior via Aza Michael addition. Firstly, SBA-15 was prepared hydrothermally, then functionalized by mono-, di- and tri-amine, and in the second step, copper (II) was anchored. The catalytic activity of these solids was evaluated at room temperature under liquid-phase conditions. Effects of catalyst nature, catalyst mass, reaction time and the starting reagents nature were investigated. Cu@SBA-15 (non-aminated) was shown to be efficient in the Aza Michael addition, but after its second re-use, a progressive decrease in the product yield was obtained due to copper leaching. The catalytic behavior of all prepared catalysts showed a selective reaction via the mono-Aza-Michael addition. Amongst all the catalysts, the one containing the monoamine-copper complex led to the highest yield. This catalyst was used in four consecutive cycles without significant loss of activity, which confirms its stability. [ABSTRACT FROM AUTHOR]

Abstract Amorphous carbon nitride a -CN 0.26 thin films were elaborated on transparent and conductive glass/indium-tin oxide (ITO) wafers to improve the electroanalytical detection of transthyretin peptide (PN) and specific amino acids (AA) from its sequence, which constitutes a great challenge for the diagnosis of transthyretin-related familial amyloïd polyneuropathy (ATTR). The naphthalene-2,3-dicarboxyaldehyde (NDA) label was used for the derivatization reaction of PN and AAs to form N-2-substituted-1-cyanobenz-[ f ]-isoindole derivatives (CBI) which are both fluorescent and electroactive. The results obtained on a -CN 0.26 were compared with those observed on glassy carbon (GC) as a reference material. It was shown that a soft anodic pre-treatment protocol on glass/ITO/ a -CN 0.26 electrode in a KCl aqueous solution drastically improved the performances of the CBI-PN and CBI-AA oxidation peak. The oxidation peak potential for all CBI derivatives varied in the same range than those measured on GC and pre-treated glass/ITO/ a -CN 0.26 , while no discrimination could be obtained on as-grown glass/ITO/ a -CN 0.26 electrodes. For almost all the tested CBI derivatives, peak areas, full-widths at peak mid-height, peak current density and their standard deviation (SD) values were improved on a pre-treated a -CN 0.26 electrode in comparison with GC. [ABSTRACT FROM AUTHOR]

Amorphous carbon nitride (a-CNX) thin films possessing different nitrogen contents (0.12 ≤ x ≤ 0.30) have been synthetized by the DC cathodic reactive magnetron sputtering technique on transparent glass/indium tin oxide (ITO) substrates. They were characterized ex-situ by using two microscopy techniques: scanning electron microscopy (SEM) and atomic force microscopy (AFM), a spectroscopic technique: X-ray photoelectron spectroscopy (XPS), and in solution by using electrochemical methods: cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results obtained with these methods have permitted to highlight why a-CN0.30, the a-CNx sample with the highest nitrogen content among those investigated in this work, behaves both as a dielectrical material (low electronic conductivity) and as an ideally polarizable interface (high polarization resistance). For this purpose, the role of both the ionic strength and the overpotential were investigated in blocking electrode conditions, i.e. only in the presence of the supporting electrolyte. It was observed that the interfacial capacitance can be strongly electrically modulated with the ionic charge concentration and with the applied overpotential. The understanding of the behaviour of a-CNx materials presents a great challenge for their integration in new microfluidic transistor type devices in view of the elaboration of polarizable interface flow-field effect transistors (PI-FFETs). [ABSTRACT FROM AUTHOR]

Amorphous carbon nitride (a-CNx) thin films were used for the first time as electrode materials in the elaboration of biofuel cell cathodes as a consequence of i) the natural presence of amine type functional groups and ii) the ease to generate carboxylic acid groups on their surface with the help of an anodic treatment. Their rich surface chemistry was exploited to investigate the influence of the orientation of immobilised laccase on their bioelectrocatalytic activity towards oxygen reduction reaction (ORR) in a direct electron transfer configuration. Among four different immobilisation strategies leading to a statistical control of the orientation and tested in this work, spontaneous adsorption of natural laccase on pristine a-CNx provided the smallest current density value (3.5 μA cm −2 ) whereas covalent grafting of oxidised laccase on anodically treated a-CNx via imine and amide bond formation using a coupling agent led to a much higher but still low 44.6 μA cm −2 current density. This substantial improvement of the current density value measured for ORR confirms that the orientation of immobilised laccase exerts a measurable influence on its bioelectrocatalytic activity towards ORR. In parallel, the surface coverage rate of enzymes showing such activity was estimated as a function of the immobilisation method by using four different techniques (current density, activity towards ABTS, XPS and AFM). It was found that only a small fraction (7.1% to the most) of the electrode surface is covered with active enzymes, whatever the immobilisation method, whereas an enzyme population corresponding (almost) to a full enzyme monolayer was actually immobilised. This observation is crucial because it strongly suggests that the development of innovative immobilisation strategies allowing an increase of the active enzyme fraction through a simultaneous optimisation of the bioelectrocatalytic activity of the enzyme and of its electronic communication with the electrode offers much more promising perspectives than the control of the orientation of the immobilised enzyme population on its own. [ABSTRACT FROM AUTHOR]

Carrier density of electrodeposited methylammonium lead iodide perovskite (CH 3 NH 3 PbI 3) can be modulated inside the 1017 to 1020 cm−3 range by carefully selecting the experimental parameters used during the last two chemical conversion steps of their synthesis. This finding has been made possible by performing systematically Mott-Schottky (MS) plots in aqueous solution on various semi-conducting CH 3 NH 3 PbI 3 perovskite samples. These latter were produced by a three-step synthesis method combining an electrodeposition step with two consecutive chemical conversion steps. In a first step, the galvanostatic electrodeposition of a lead dioxide (PbO 2) thin film is carried out. This latter is then converted into lead (II) iodide (PbI 2) by immersion in a HI/ethanol solution, this latter being then itself turned in a third and last step into the well-known CH 3 NH 3 PbI 3 perovskite by a new immersion step in a methylammonium iodide (MAI)/isopropanol solution. This very simple and highly reproducible synthesis method allows the production of perovskite thin films on large surfaces, unlike many other synthesis methods of perovskite thin films. In parallel to the determination of p-type character, carrier concentration and flat band potential of the perovskite samples using Mott-Schottky plots, their chemical composition, their morphology and their crystallinity were characterized by using scanning electron microscopy (SEM) and X-Ray Diffraction (XRD) and compared with those of the products obtained at the end of each of the two first steps, i.e. PbO 2 and PbI 2 respectively. Interestingly, it was shown that the final product is not always a pure p-type perovskite thin film as various amounts of lead (II) iodide (PbI 2) can be detected depending on the experimental parameters used during the two consecutive chemical conversion steps. The main result of this study is that the dopant concentration of perovskite thin films was shown to be inversely proportional to the amount of the remaining PbI 2 impurities detected in the bulk of perovskite thin films. • CH 3 NH 3 PbI 3 perovskite thin films were synthesized using electrodeposition and two chemical conversion steps. • They are p-type semiconductors with a bandgap energy close to 1.57 eV. • They all contain a PbI 2 fraction that depends on the two immersion durations. • When the PbI 2 % decreases, the carrier concentration increases over three decades. • Our synthesis method is promising for the fast and large scale production of tunable perovskites. [ABSTRACT FROM AUTHOR]

ToF-SIMS and XPS are combined to study the adsorption of tetradecyl-benzyldimethyl-ammonium (BDA-C14) bromide corrosion inhibitor on carbon steel surface. BDA-C14 forms a protective layer with N-containing polar head group interacting with carbon steel surface. The adsorbed inhibitor surface coverage strongly depends on immersion time and inhibitor concentration. A maximum and uniform coverage is found for sufficiently long exposure times at a critical inhibitor concentration of about 25 ppm w. The uniform adsorbed inhibitor layer formed on the surface mitigates the formation of iron chloride/hydroxide intermediates and thus enhances the corrosion protection of carbon steel in aggressive environment. • The adsorption of BDA-C14 corrosion inhibitor on carbon steel surface was studied by ToF-SIMS and XPS. • The inhibitor forms a protective layer with N-containing polar head group interacting with carbon steel surface. • The adsorbed inhibitor surface coverage strongly depends on immersion time and inhibitor concentration. • The critical concentration for a maximum and uniformed inhibitor coverage on carbon steel is determined. • The uniform adsorbed inhibitor layer on carbon steel can mitigate the formation of iron chloride/hydroxide intermediates. [ABSTRACT FROM AUTHOR]

A nanostructured polypyrrole powder was synthesized in a previous work from the oxidation of pyrrole by a nanostructured MnO 2 powder used simultaneously as an oxidizing agent and a sacrificial template in a redox heterogeneous mechanism. In this study, this original PPy powder was used as an active additive material with different ratio in carbon/carbon symmetrical supercapacitors whose performances were studied by cyclic voltammetry and electrochemical impedance spectroscopy (EIS) using a Swagelok-type cell. From the EIS spectra, the complex capacitance was extracted using a model involving two Cole–Cole type complex capacitances linked in series. The specific capacitance values evaluated by EIS and cyclic voltammetry are in a good agreement between them. The results show that the addition of nanostructured polypyrrole powder improves significantly the specific capacitance of the carbon electrode and consequently the performances of carbon/carbon supercapacitors. The original and versatile synthesis method used to produce this polypyrrole powder appears to be attractive for large scale production of promising additives for electrode materials of supercapacitors. [ABSTRACT FROM AUTHOR]

Cerium oxide (CeO 2 ) nanoparticles (NPs) possessing defined size and crystallinity have been synthesised by a co-precipitation method. The effect of several parameters, such as the nature of the solvent and the calcination process, on the crystallite size was studied by XRD, TEM and BET methods. These CeO 2 nanoparticles were then incorporated in dodecylsulfate (DS) doped PPy films during their electrodeposition in potentiodynamic conditions in order to produce PPy-DS/CeO 2 NPs nanocomposite thin films on gold coated quartz crystals. Simultaneous EQCM experiments revealed successful incorporation of increasing amounts of cerium oxide nanoparticles in the polypyrrole matrix during each of the consecutive CV scans. This was confirmed using FEG-SEM and EDS microanalysis. The ion exchange phenomena occurring in the resulting nanocomposite materials were studied by ac -electrogravimetry in NaCl aqueous electrolyte. PPy-DS films appear to be mainly cation exchangers, independently from the incorporation of CeO 2 nanoparticles (NPs), even though chloride anions in smaller amounts, and free water molecules, are simultaneously transferred at the film/electrolytic solution interface. This study also reveals that the kinetics of Cl − ion insertion occurring at the film/electrolyte interface upon oxidation is persistently slower in PPy-DS/CeO 2 NPs films than in PPy-DS films throughout the entire potential window of investigation. However, the relative concentration changes of Cl − ions in PPy-DS/CeO 2 NPs films is about two times greater than that occurring in pristine PPy-DS films. Such conclusion tends to demonstrate that CeO 2 NPs have the ability to modify the morphology of electrodeposited PPy-DS thin films as well as their subsequent permeability towards ions contained in the electrolytic solution, possibly via the perturbation of polymer chain interactions and organisation. [ABSTRACT FROM AUTHOR]

Surface activation of polymers by atmospheric pressure plasma is an economically important process for bonding technologies. Although most of the studies are focused on the modification of the surface chemistry, this study investigates the modification of the topmost surface and the deeper layers of a polyamide-6 sheet treated by an open-air atmospheric plasma jet system. The plasma jet used in this study is a unique combination of highly reactive species (e.g. O°, °OH ...) and a high temperature gas estimated (from 600-1 000 K) which leads to surface functionalization, amorphization and polymorphism modification. The results have shown that an amorphization of the polyamide occurs on the top surface. Moreover, a crystallization of the amorphous phase in the α form was also highlighted in the depth of the material. [ABSTRACT FROM AUTHOR]

A fluorocarbonyl terminated ferrocene based redox probe was synthesized and characterized using infrared spectroscopy and nuclear magnetic resonance. It was then successfully grafted on various amorphous carbon nitride (a-CNx) samples (0.12↜x↜0.27) via the formation of a -CO-NH- type linkage with surface amine groups, whose spontaneous formation on the surface of a-CNx materials was thus proved and exploited. Cyclic voltammetry experiments were carried out in an acidic aqueous solution in the presence of this freely diffusing redox probe, in order to identify its electrochemical behavior. By comparison, CV experiments carried out on the modified a-CNx electrodes in the same blank electrolytic solution undoubtedly confirmed the presence of electroactive sub-monolayers, in spite of distortions of the resulting voltammograms. These latter were shown to reflect the influence of bulk atomic nitrogen content on the electrochemical reactivity of a-CNx materials. The grafted surface amine percentage deduced from the charge passed during oxidation of grafted ferrocene moieties was found to decrease from 6.5% for a-CN0.12 down to 1.1% for a-CN0.27. This trend is expected to reflect the trend in surface concentration of reactive amine groups as a function of bulk atomic nitrogen content. [ABSTRACT FROM AUTHOR]

Highlights: [•] A nanostructured polypyrrole powder is synthesized via a redox core–shell mechanism. [•] For that, a nanostructured MnO2 powder is used as oxidizing sacrificial template. [•] Reaction product is a pure and conducting PPy powder with a large specific area. [•] Its stoichiometry and production of soluble Mn2+ cations are clearly evidenced. [•] These new data will strengthen control in the synthesis of MnO2/PPy composite materials. [Copyright &y& Elsevier]

Cancer cells accommodate multiple genetic and epigenetic alterations that initially activate intrinsic (cell-autonomous) and extrinsic (immune-mediated) oncosuppressive mechanisms. Only once these barriers to oncogenesis have been overcome can malignant growth proceed unrestrained. Tetraploidization can contribute to oncogenesis because hyperploid cells are genomically unstable. We report that hyperploid cancer cells become immunogenic because of a constitutive endoplasmic reticulum stress response resulting in the aberrant cell surface exposure of calreticulin. Hyperploid, calreticulin-exposing cancer cells readily proliferated in immunodeficient mice and conserved their increased DNA content. In contrast, hyperploid cells injected into immunocompetent mice generated tumors only after a delay, and such tumors exhibited reduced DNA content, endoplasmic reticulum stress, and calreticulin exposure. Our results unveil an immunosurveillance system that imposes immunoselection against hyperploidy in carcinogen- and oncogene-induced cancers. [ABSTRACT FROM AUTHOR]

Abstract: In this work, a-CNx films prepared by DC magnetron sputtering on stainless steel substrate have been investigated as electrode materials. While their wide potential window was confirmed as a property shared by boron doped diamond (BDD) electrodes, their electrochemical activity with respect to fast and reversible redox systems, [Ru(NH3)6]3+/2+, [Fe(CN)6]3−/4− and [IrCl6]2−/3−, was assessed by Electrochemical Impedance Spectroscopy (EIS) after cathodic or anodic electrochemical pre-treatments or for as grown samples. It was shown for the three systems that electrochemical reactivity of the a-CNx films was improved after the cathodic pre-treatment and degraded after the anodic one, the apparent heterogeneous rate constant k 0app being decreased by at least one order of magnitude for the latter case. A high k 0app value of 0.11cms−1 for [IrCl6]2−/3− was obtained, close to the highest values found for BDD electrodes. [Copyright &y& Elsevier]

Abstract: An electrolysis technique at a constant potential was used to develop a highly reproducible and fast elaboration method of adherent manganese dioxide thin films on a glassy carbon electrode from aqueous solutions containing sulfuric acid and manganese sulfate. The resulting films were found to have a nanostructured character presumably due rather to birnessite (δ-MnO2) than to γ-MnO2, as suggested by their Raman and XRD signatures. They lead to modified electrodes that present an obvious although complex pH dependent potentiometric response. This sensor indeed showed a single slope non-Nernstian linear behaviour over the 1.5–12 pH range for increasing pH direction (“trace”), whereas a Nernstian two slopes linear behaviour was observed for decreasing pH direction (“re-trace”). Preliminary EIS experiments carried out at a pH value of 1.8 seem to reveal a sensitivity mechanism based on proton insertion process at least at highly acidic pH values. [Copyright &y& Elsevier]

Abstract: The normal and lateral spring constants of rectangular silicon AFM cantilevers bearing pyramidal silicon tips were accurately calibrated using a procedure that takes into account their tilt compared to horizontal orientation and their trapezoidal cross section. Such systems were used to carry out nanoscratching tests in air on technical substrates presenting a moderate roughness (RMS≈40nm) and made either from bulk copper or from cuprous oxide thin films electrogenerated on copper. The various events occurring during these nanoscratching procedures were characterized in details. In particular, the features of the scars appearing on the scratched zones and SEM observations of the AFM tips used during the nanoscratching procedures are described and exploited to establish a better understanding of the effects of the nanoscratching procedures on the targeted samples. In the case of electrodeposited Cu2O films, these effects are discussed with the help of chemical and structural characterizations using XPS and XRD studies. All this set of information is used i) to describe the history of the nanoscratching tests and ii) to compare mechanical resistance of bulk copper and electrogenerated Cu2O thin films using these nanoscratching tests carried out in air. The wear mechanism occurring during nanoscratching tests is discussed for both kinds of samples and compared with the one observed during erosion in erosion–corrosion tests. [ABSTRACT FROM AUTHOR]

Abstract: Electrochemical activity, morphology and surface electrical conductivity of Boron-Doped Polycrystalline Diamond films prepared by MPCVD have been investigated. Heterogeneous apparent rate constants of three different redox systems, [Fe(CN)6]3−/4−, [IrCl6]2−/3− and [Ru(NH3)6]3+/2+ have been measured by both Cyclic Voltammetry and Electrochemical Impedance Spectroscopy on<100>textured films with a predominance of (111) faces: first measurements have been done with [Fe(CN)6]3−/4− only on as grown samples, and secondly after a mild electrochemical pretreatment the three redox systems have been investigated. “As-grown” samples showed a moderate average activity which was related to the presence of a minority of electronically conducting areas among insulating zones. Electrochemical treatment in neutral conditions substantially increased the activity and heterogeneous apparent rate constants k app for the three couples were measured in the range of 10−2 cms−1 with a good stability in time. Current-sensing AFM images performed ex situ showed that the electrochemically pre-treated material presented a high superficial conductivity whereas the grown sample showed major area of low conductivity. [Copyright &y& Elsevier]

Abstract: The local wall shear stress (WSS) mapping in the rotating cage (RC) has been obtained from measuring the diffusion current due to the electrochemical reduction of methyl viologen used as tracer system for both Newtonian and non-Newtonian solutions. The latter were achieved with oleyltrimethyl ammonium, a cationic surfactant, and sodium salicylate as counter-ion, forming thread-like micelles which induce drag reduction conditions. The maximum WSS values were detected in the middle of the coupon in agreement with observation of corroded coupons in erosion–corrosion tests. Maximum values of 65% for drag reduction were measured at the same locations. [Copyright &y& Elsevier]

Femtosecond pulsed laser ablation has been used for the deposition of various thin films by co-ablating pure graphite and pure metallic targets (nickel or tantalum) under vacuum conditions with an amplified Ti:sapphire laser working at 800 nm, with about 1.5 mJ per pulse at a repetition rate of 1 kHz. The plasma plume created during the femtosecond pulsed laser deposition process has been investigated, by fast imaging and spectroscopic characterizations, depending on the ablated target and deposition conditions. Particular attention has been paid to the correlation between the film nanostructure and the plasma plume properties, in terms of ejected species and energies of impinging species on the substrate. The tantalum clusters in the tantalum-doped carbon films appear under two crystalline phases: a stable phase (α-Ta) corresponding to that of the target, and a metastable phase (β-Ta), already observed at high temperatures. The presence of this metastable phase (β-Ta) is correlated to the temperature of the clusters measured from the plasma plume investigation. [ABSTRACT FROM AUTHOR]

Abstract: An unknown corrosion process producing dendrites was recently found to take place at copper patterns immersed in oxalic acid aqueous solutions in the course of the post-chemical–mechanical polishing of integrated microcircuits (ICs). We report here investigations of this corrosion phenomenon in ICs using atomic force microscopy (AFM), cyclic voltammetry and Raman spectroscopy. AFM first allowed an accurate morphological characterisation of the copper patterns and their surroundings while cyclic voltammetry was used to identify their electrochemical reactivity in oxalic acid aqueous solutions. In situ AFM experiments carried out in this same aqueous media in open circuit conditions unambiguously showed a progressive and partial dissolution of copper patterns as well as the formation of a ring type structure. Raman spectroscopy was used on gold supported electrogenerated copper films to identify the precipitation or adsorption products resulting from the electrochemistry of the copper/oxalic acid system as a function of the applied potential and the pH of the oxalic acid aqueous solutions. The collected results rather suggest a two-step galvanic corrosion phenomenon involving the tantalum barrier, copper seed layer and electrodeposited copper. [Copyright &y& Elsevier]

Cylindrical micelles prepared in aqueous solutions from cationic surfactants octadecyl trimethylammonium (OTA) or cetyltrimethylammonium (CTA) and parachlorobenzoate (PCB) counterion were successfully imaged after evaporation of water using tapping mode atomic force microscopy (TM-AFM) onto very smooth gold and glass substrates. With the help of the obtained topography AFM images, it was shown that the micellar structures are preserved on gold substrates after evaporation of the solvent despite the new set of stresses due mainly to capillary forces and dehydration. The influence of the substrate on the resulting micellar morphology observed in air was investigated for these two materials:  cylindrical micelles were evidenced as loosely adherent on gold surface in the presence of parachlorobenzoate (PCB) and identical, geometrically speaking, to those known to exist in aqueous solutions. In this situation, topographic AFM images allowed us to determine accurately their geometrical characteristics such as diameter and length in the nanometer range. On the other hand, AFM images obtained in air on glass surfaces revealed micellar structures that are different from those existing in the bulk of the solution. Indeed, bilayer-type micelles with a thickness close to twice the surfactant monomer expected length were observed, indicating that the well-established and strong influence of glass on micelle geometry at the glass/solution interface is maintained after evaporation of water. These results have been analyzed on the basis of positive charge of gold deduced from electrochemical impedance spectroscopy (EIS) and Raman spectroscopy measurements on one hand and of the negative charge of glass on the other hand. Although these results appeal to new theoretical considerations dealing with dynamics of evaporation of micellar solution drops and/or with counterion contributions to macromolecular interactions in aqueous solutions and in air, this new AFM imaging method appears to be the more adequate one to image and measure the micelles formed in the presence of water. [ABSTRACT FROM AUTHOR]

We report in this paper on the electrochemical formation of nickel tetrasulfonated phthalocyanine (NiTSPc) based films on bulk Pt disk microelectrodes (diameter d=50 μm) and thin-film Pt microdisk (diameter d=10 μm) arrays for the realisation of Pt based nitric oxide sensors. Our results show that, despite the simultaneous formation of platinum oxides, NiTSPc deposited film offers an interesting alternative to elaborate new electrode configuration. [Copyright &y& Elsevier]

• Integration of amorphous carbon nitride (a-CNx) was reported in microfluidic. • Hydrodynamic voltammetry and EIS were used for characterization under flow. • The developed electrochemical biosensor is robust, label free, and stable. • We evidenced how an activation procedure leads more DNA probes collection. • The use of a-CNx microelectrodes for DNA detection is evidenced. This study presents the use of new kind of carbon electrode materials as ultramicroelectrodes (UMEs) in the field of electrochemical DNA biosensors which has already been proven to be effective in protocols to DNA sequences hybridization. In contrast to other carbon materials such as diamond like carbon, that are difficult to integrate in microfluidic devices due to their high temperature deposition, amorphous carbon nitride (a-CNx) is easily synthesized at room temperature on various materials using sputtering techniques. Here, we report a-CNx use as microband electrodes in Glass/PDMS microfluidic devices. a-CNx electrodes were activated and then biofuntionalized by covalent grafting of a DNA probe as self-assembled monolayer (SAM) with a view to future development of a detection platform targeting circulating DNA or RNA sequences in microfluidic channels. [ABSTRACT FROM AUTHOR]

[Display omitted] • Graphite was nanostructured with carbon nanowalls. • The carbon surface was functionalized using atmospheric pressure plasma jet. • A biocathode has been developed based on immobilized Laccase. • The highest measured current density was obtained with pre-oxidized laccase. An enzymatic biofuel cell cathode was elaborated by nano-structuration and functionalization of graphite using two consecutive plasma treatments before immobilization of laccase as a biocatalyst to perform oxygen reduction reaction (ORR) by direct electron transfer ((DET). Nano-structuration of graphite surfaces by synthesis of vertical graphen-like carbon nanowalls (CNWs) was performed by microwave excited plasma enhanced chemical vapor deposition (PECVD). Atmospheric pressure plasma jet (APPJ) system was then used to functionalize chemically the CNWs surface via a rapid and dry route. A partial fractional design evidenced two significant parameters of the APPJ treatment in terms of ORR current density: the treatment time and the inter-distance between the plasma jet and the surface of the carbon material. With the optimized APPJ treatment parameters, a four-fold enhancement of the ORR current density (-440 ± 70 μA/cm2) could be obtained on CNWs, compared to graphite electrodes. The best current density obtained was about −1 mA/cm2 with oxidized laccase covalently immobilized on the electrode without any agitation of the solution, confirming the main importance of enzyme orientation on the electrode surface for efficient DET transfer, the relevance of electrode nanostructuration and the advantage of covalent linking of the protein on the electrode surface. [ABSTRACT FROM AUTHOR]