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An original versatile methodology for molecular grafting on different surfaces via the photoinduced formation of a covalent bond based on a diazirine group is reported. The synthesis and electrochemical behavior of a new diazirine derivative which acts as a molecular linking bridge bearing both a photoactivatable covalent binding group (diazirine) and a non-covalent binding group (pyrene) is described. The resulting pyrene-diazirine was electropolymerized onto a platinum electrode and under UV irradiation was successfully used to graft ferrocenemethanol and glucose oxidase (model small molecule and protein, respectively), conferring specific properties on the resulting materials. Furthermore, the immobilization of the diazirine derivative onto multi-walled carbon nanotubes (MWCNT) by π-stacking interaction or by electropolymerization onto both bare and MWCNT-coated platinum electrodes enabled photografting of glucose oxidase. Keywords: Diazirine, Pyrene, Photografting, Electropolymerization, Glucose oxidase, Carbon nanotubes

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Patients infected with hepatitis B and C viruses have a systemic infection. These two viruses are found in the bloodstream, colonize several sites, multiply and last in the body for years. This presence causes an immunological response more or less important depending on the individuals and is responsible in particular for kidney damage. In addition, we note that all patients with these viruses do not develop the same types of kidney damage. Why? Can we establish a link between kidney damage and liver damage? Is kidney disease more serious in patients diagnosed with hepatitis? What are the most common clinical manifestations in these patients? The purpose of this study is to find the rule between kidney disease and chronic infection with HVB and HVC . It's a retrospective study about 51 patients hospitalized between 2016-2017 at the CHU of Cluj-Napoca in Romania with systemic infection by hepatitis viruses and or hepatitis C with different renal damage, Les patients infectés par les virus de l’hépatite B et C présentent une infection systémique. En effet, ces 2 virus se retrouvent dans la circulation sanguine, colonisent plusieurs sites, se multiplient et perdurent dans l’organisme durant des années. Cette présence entraine une réponse immunologique plus ou moins importante en fonction des individus et est responsable notamment des atteintes rénales. De plus, on constate que tous les patients porteurs de ces virus ne développent pas les mêmes types d’atteintes rénales. Pourquoi ? Pouvons-nous établir un lien entre l’atteinte rénale et l’atteinte hépatique ? La maladie rénale est-t-elle plus grave chez les patients diagnostiqués avec une hépatite ? Quelles sont les manifestations cliniques les plus fréquentes chez ces patients ? Le but de notre étude est d’établir un lien entre l’infection par les virus de l’hépatite B et de l’hépatite C et l’apparition de manifestations biologiques responsables d’une maladie rénale chronique. L'étude porte sur 51 patients hospitalisés entre 2016-2017 au CHU de Cluj-Napoca en Roumanie présentant une infection systémique par les virus de l'hépatite et ou et l'hépatite C avec différentes atteintes rénales.

International audience; A simple and highly sensitive approach for the detection of the anti-neoplastic drug gemcitabine is presented, based on a one-step electropolymerized molecularly imprinted microporous-metal-organic-framework. The sensitive layer was prepared by electropolymerization of the aniline moieties of p-aminothiophenol- gold nanoparticles on the surface of gold electrodes tethered with p-aminothiophenol, in the presence of gemcitabine as a template molecule. Experimental parameters that control the performance of the sensor were investigated and optimized. Under optimal conditions a calibration curve was obtained in the linear range from 3.8 fM to 38 nM with a limit of detection of 3 fM. The obtained imprinted sensor has the advantages of easy manufacture, high sensitivity and selectivity and good reproducibility. Furthermore the feasibility of the proposed technique has been investigated on spiked serum samples and infusion solution containing gemcitabine.

An original interfacial hybrid cross-linker molecule combined electrochemical and photochemical properties by substitution of two functional groups, pyrene, and diazirine. The first group enables anchoring by strong π-stacking interaction or by electropolymerization onto multi-walled carbon nanotubes (MWCNT). The other photoreactive group allows the covalent link with biomolecules under long-wavelength UV illumination. Diazirine was chosen due to its ability to photogenerate high reactive radicals under UV irradiation. The photoreactivity of these immobilized nanostructured conductive surfaces was tested towards the covalent attachment of tyrosinase which is well known to oxidize a large range of phenolic compounds and its yield and availability was evaluated by amperometric measurements of catechol by using molecular dioxygen. The architecture exhibiting the best analytical characteristics obtained for catechol was then chosen to detect dopamine.

A sensitive electrochemical molecularly imprinted sensor was developed for the detection of estradiol, by electropolymerization of p-aminothiophenol functionalized gold nanoparticles in the presence of estradiol as template molecule. The extraction of the template leads to the formation of cavities that are able to recognize and bind estradiol with high affinity. The performance of the developed sensor for the detection of estradiol was investigated by linear sweep voltammetry using a hexacyanoferrate/hexacyanoferrite solution as redox probe. The molecularly imprinted sensor exhibits a broad linear range, between 3.6 fM and 3.6 nM and a limit of quantification of 1.09 fM. Compared to the non-imprinted sensor, the imprinted sensor exhibits high affinity for the binding of estradiol. Moreover, selectivity studies, performed towards binding of testosterone, a hormone with similar chemical structure, proved high sensor selectivity. Furthermore, the molecularly imprinted sensor was applied for the analysis of spiked river samples with good recoveries. Keywords: Molecularly imprinted polymer, p-Aminothiophenol, Gold nanoparticles, Estradiol

The performances of carboxylate- and cyclam-modified graphite felt electrodes prepared by different electrografting methods for trace analysis of copper (II) were compared to determine the influence of the immobilization process of the linkers on the sensor properties. The derivatization performed by cathodic reduction of diazonium salts and by anodic oxidation of amines in organic and aqueous media was first evaluated by cyclic voltammetry and X-ray photoelectron spectroscopy analyses, showing a higher surface coverage for the reduction process. Cyclam was subsequently attached on the COOH-modified graphite felts by a coupling reaction. The modified electrodes were then employed in a flow analytical system for trace analysis of copper (II) ions. The influence of the surface coverage and the nature of the linker on the electrochemical signal obtained by linear sweep stripping voltammetry analysis after a preconcentration step performed at open circuit was highlighted. The selectivity estimated in the presence of lead used as a common ion interferent was higher when a selective receptor was used and depends on the nature of the linker.

International audience; This work describes the preparation and characterization of smectite clay partially exchanged with tetrabutylammonium ions (TBA(+)) and its subsequent deposition onto glassy carbon electrode (GCE) for application to the preconcentration electroanalysis of metal ions (Cd, Pb, and Cu). Such partial exchange of TBA(+) induces the expansion of the interlayer region between the clay sheets (as ascertained by XRD) while maintaining its ion exchange capacity, which resulted in enhanced mass transport rates (as pointed out by electrochemical monitoring of permeability properties of these thin (organo)clay films on GCE). This principle was applied here to the anodic stripping square wave voltammetric analysis of metal ions after accumulation at open circuit. Among others, detection limits as low as 3.6 x 10(-8) M for copper and 7.2 x 10(-8) M for cadmium have been achieved.

Due to the rapidity and the effectiveness of the method, the reduction of diazonium salts has been widely used to functionalize electrodes for sensor applications. However, the resulting organic film usually designed to provide complexing capabilities for the species to be determined could affect the sensor properties. The electrochemical reduction of 4-methoxybenzene diazonium salt on graphite felt that leads to the formation of an organic film with unexpected high affinity for copper ions is presented. This property combined with a flow electrochemical system led us to achieve a sensitive sensor for copper detection, with good selectivity towards some common interferent ions. Keywords: Sensor, Graphite felt, Diazonium salts, Copper, Flow

We report the combination of latex nanosphere lithography with electropolymerization of N-substituted pyrrole monomer bearing a nitrilotriacetic acid (NTA) moiety for the template-assisted nanostructuration of poly(pyrrole-NTA) films and their application for biomolecule immobilization. The electrodes were modified by casting latex beads (100 or 900 nm in diameter) on their surface followed by electropolymerization of the pyrrole-NTA monomer and the subsequent chelation of Cu(2+) ions. The dissolution of the nanobeads leads then to a nanostructured polymer film with increased surface. Thanks to the versatile affinity interactions between the (NTA)Cu(2+) complex and histidine- or biotin-tagged proteins, both tyrosinase and glucose oxidase were immobilized on the modified electrode. Nanostructuration of the polypyrrole via nanosphere lithography (NSL) using 900- and 100-nm latex beads allows an increase in surface concentration of enzymes anchored on the functionalized polypyrrole electrode. The nanostructured enzyme electrodes were characterized by fluorescence microscopy, 3D laser scanning confocal microscopy, and scanning electron microscopy. Electrochemical studies demonstrate the increase in the amount of immobilized biomolecules and associated biosensor performances when achieving NSL compared to conventional polymer formation without bead template. In addition, the decrease in nanobead diameter from 900 to 100 nm provides an enhancement in biosensor performance. Between biosensors based on films polymerized without nanobeads and with 100-nm nanobeads, maximum current density values increase from 4 to 56 μA cm(-2) and from 7 to 45 μA cm(-2) for biosensors based on tyrosinase and glucose oxidase, respectively.

International audience; A flow sensor for trace analysis of zinc, using graphite felt as working electrode is reported here. A flow cell, well-adapted to 3-D porous electrodes and capable to do both the preconcentration step at a cathodic potential and the stripping of the zinc was successfully developed. It was demonstrated that this cell allows to obtain better electrochemical signals for Zn(2+) compared to a standard three-electrodes cell and that the percolation during accumulation increases the kinetics of electrodeposition. The influence on Zn(2+) signal of the deposition potential, the time of deposition and the flow rate was studied. The resulting sensor shows a linear response towards Zn(2+) with a linear range of 10(-6)-10(-4)M and a limit of detection of 5×10(-7) M for an analysis time of 5 min. The interferences study showed that the Cr(3+), Pb(2+), Cd(2+) ions have a small effect on the Zn electrochemical signal, whereas Fe(3+), Cu(2+), Co(2+) and Ni(2+) ions strongly influence it. The electrode was tested on real samples (tap water spiked with Zn(2+), food supplement) with a good recovery by applying the standard addition method.

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