The Experts below are selected from a list of 381 Experts worldwide ranked by ideXlab platform

Robert S Marks - One of the best experts on this subject based on the ideXlab platform.

  • nanostructured photoactivatable electrode surface based on pyrene diazirine
    Electrochemistry Communications, 2017
    Co-Authors: Oana Hosu, Kamal Elouarzaki, Karine Gorgy, Cecilia Cristea, Robert Sandulescu, Robert S Marks, Serge Cosnier
    Abstract:

    Abstract 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.

  • Nanostructured photoactivatable electrode surface based on pyrene diazirine
    Elsevier, 2017
    Co-Authors: Oana Hosu, Kamal Elouarzaki, Karine Gorgy, Cecilia Cristea, Robert Sandulescu, Robert S Marks, Serge Cosnier
    Abstract:

    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 nanotube

  • biofunctionalization of multiwalled carbon nanotubes by irradiation of electropolymerized poly pyrrole diazirine films
    Chemistry: A European Journal, 2013
    Co-Authors: Vladislav Papper, Kamal Elouarzaki, Karine Gorgy, Robert S Marks, Serge Cosnier, Ayrine Sukharaharja
    Abstract:

    A photoactivatable poly(pyrrole-diazirine) film was synthesized and electropolymerized as a versatile tool for covalent binding of laccase and glucose oxidase on multiwalled carbon nanotube coatings and Pt, respectively. Irradiation of the functionalized nanotubes allowed photochemical grafting of laccase and its subsequent direct electrical wiring, as illustrated by the electrocatalytic reduction of oxygen. Moreover, covalent binding of glucose oxidase as model enzyme, achieved by UV activation of electropolymerized pyrrole-diazirine, allowed a glucose biosensor to be realized. This original method to graft biomolecules combines electrochemical and photochemical techniques. The simplicity of this new method allows it to be extended easily to other biological systems.

Serge Cosnier - One of the best experts on this subject based on the ideXlab platform.

  • nanostructured photoactivatable electrode surface based on pyrene diazirine
    Electrochemistry Communications, 2017
    Co-Authors: Oana Hosu, Kamal Elouarzaki, Karine Gorgy, Cecilia Cristea, Robert Sandulescu, Robert S Marks, Serge Cosnier
    Abstract:

    Abstract 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.

  • Nanostructured photoactivatable electrode surface based on pyrene diazirine
    Elsevier, 2017
    Co-Authors: Oana Hosu, Kamal Elouarzaki, Karine Gorgy, Cecilia Cristea, Robert Sandulescu, Robert S Marks, Serge Cosnier
    Abstract:

    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 nanotube

  • biofunctionalization of multiwalled carbon nanotubes by irradiation of electropolymerized poly pyrrole diazirine films
    Chemistry: A European Journal, 2013
    Co-Authors: Vladislav Papper, Kamal Elouarzaki, Karine Gorgy, Robert S Marks, Serge Cosnier, Ayrine Sukharaharja
    Abstract:

    A photoactivatable poly(pyrrole-diazirine) film was synthesized and electropolymerized as a versatile tool for covalent binding of laccase and glucose oxidase on multiwalled carbon nanotube coatings and Pt, respectively. Irradiation of the functionalized nanotubes allowed photochemical grafting of laccase and its subsequent direct electrical wiring, as illustrated by the electrocatalytic reduction of oxygen. Moreover, covalent binding of glucose oxidase as model enzyme, achieved by UV activation of electropolymerized pyrrole-diazirine, allowed a glucose biosensor to be realized. This original method to graft biomolecules combines electrochemical and photochemical techniques. The simplicity of this new method allows it to be extended easily to other biological systems.

Oana Hosu - One of the best experts on this subject based on the ideXlab platform.

  • nanostructured photoactivatable electrode surface based on pyrene diazirine
    Electrochemistry Communications, 2017
    Co-Authors: Oana Hosu, Kamal Elouarzaki, Karine Gorgy, Cecilia Cristea, Robert Sandulescu, Robert S Marks, Serge Cosnier
    Abstract:

    Abstract 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.

  • Nanostructured photoactivatable electrode surface based on pyrene diazirine
    Elsevier, 2017
    Co-Authors: Oana Hosu, Kamal Elouarzaki, Karine Gorgy, Cecilia Cristea, Robert Sandulescu, Robert S Marks, Serge Cosnier
    Abstract:

    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 nanotube

František Tureček - One of the best experts on this subject based on the ideXlab platform.

  • electron transfer reduction of the diazirine ring in gas phase peptide ions on the peculiar loss of nh4o from photoleucine
    Journal of the American Society for Mass Spectrometry, 2015
    Co-Authors: Aleš Marek, Christopher J Shaffer, Kristina Slovakova, Kenneth J Laszlo, Matthew F Bush, František Tureček
    Abstract:

    Electron transfer to gas-phase peptide ions with diazirine-containing amino acid residue photoleucine (L*) triggers diazirine ring reduction followed by cascades of residue-specific radical reactions. Upon electron transfer, substantial fractions of (GL*GGR +2H)+● cation-radicals undergo elimination of [NH4O] radicals and N2H2 molecules from the side chain. The side-chain dissociations are particularly prominent on collisional activation of long-lived (GL*GGR +2H)+● cation-radicals formed by electron transfer dissociation of noncovalent peptide-18-crown-6-ether ion complexes. The ion dissociation products were characterized by multistage tandem mass spectrometry (MSn) and ion mobility measurements. The elimination of [NH4O] was elucidated with the help of 2H, 15 N, and 18O-labeled peptide ions and found to specifically involve the amide oxygen of the N-terminal residue. The structures, energies, and electronic states of the peptide radical species were elucidated by a combination of near-UV photodissociation experiments and electron structure calculations combining ab initio and density functional theory methods. Electron transfer reaching the ground electronic states of charge reduced (GL*GGR +2H)+● cation-radicals was found to reduce the diazirine ring. In contrast, backbone N − Cα bond dissociations that represent a 60%–75% majority of all dissociations because of electron transfer are predicted to occur from excited electronic states.

  • Collision-Induced Dissociation of Diazirine-Labeled Peptide Ions. Evidence for Brønsted-Acid Assisted Elimination of Nitrogen
    Journal of The American Society for Mass Spectrometry, 2014
    Co-Authors: Aleš Marek, František Tureček
    Abstract:

    Gas-phase dissociations were investigated for several peptide ions containing the Gly-Leu* N-terminal motif where Leu* was a modified norleucine residue containing the photolabile diazirine ring. Collisional activation of gas-phase peptide cations resulted in facile N_2 elimination that competed with backbone dissociations. A free lysine ammonium group can act as a Brønsted acid to facilitate N_2 elimination. This dissociation was accompanied by insertion of a lysine proton in the side chain of the photoleucine residue, as established by deuterium labeling and gas-phase sequencing of the products. Electron structure calculations were used to provide structures and energies of reactants, intermediates, and transition states for Gly-Leu*-Gly-Gly-Lys amide ions that were combined with RRKM calculations of unimolecular rate constants. The calculations indicated that Brønsted acid-catalyzed eliminations were kinetically preferred over direct loss of N_2 from the diazirine ring. Mechanisms are proposed to explain the proton-initiated reactions and discuss the reaction products. The non-catalyzed diazirine ring cleavage and N_2 loss is proposed as a thermometer dissociation for peptide ion dissociations. Fig. a ᅟ

Yoshihito Ueno - One of the best experts on this subject based on the ideXlab platform.

  • diazirine containing tag free rna probes for efficient risc loading and photoaffinity labeling of microrna targets
    Bioorganic & Medicinal Chemistry Letters, 2018
    Co-Authors: Kosuke Nakamoto, Yukihiro Akao, Yoshihito Ueno
    Abstract:

    We designed and synthesized a photo-reactive and tag-free RNA probe for the identification of microRNA (miRNA) targets. To synthesize the RNA probe, we designed a novel nucleoside analog 1-O-[3-ethynyl-5-(3-trifluoromethyl-3H-diazirine-3-yl)]benzyl-β-d-ribofuranose containing aryl trifluoromethyl diazirine and ethynyl moieties. The RNA probe containing this analog was observed to form crosslinks with complementary RNA by UV irradiation and was rapidly tagged by Cu-catalyzed azide alkyne cycloaddition (CuAAC). In addition, the tag-free and photo-reactive miRNA-145 probe showed comparable gene silencing activity to that of unmodified miRNA-145. Therefore, miRNA probes containing the nucleoside analog are promising candidates for the identification of target mRNAs of miRNAs.

  • diazirine containing rna photo cross linking probes for capturing microrna targets
    Journal of Organic Chemistry, 2014
    Co-Authors: Kosuke Nakamoto, Yoshihito Ueno
    Abstract:

    Here, we report the applicability of diazirine-containing RNA photo-cross-linking probes for the identification of microRNA (miRNA) targets. The RNA cross-linking probes were synthesized by substituting the RNA nucleobases with nucleoside analogues such as 1-O-[3-(3-trifluoromethyl-3H-diazirin-3-yl)]benzyl-β-d-ribofuranose or 1-O-[4-(3-trifluoromethyl-3H-diazirin-3-yl)]benzyl-β-D-ribofuranose that carry aryl trifluoromethyl diazirine moieties. The probes were successfully cross-linked with synthetic RNAs containing the four natural nucleosides on the opposite site of the nucleoside analogues. Furthermore, it was found that miRNAs containing these analogues were effective in regulating the expression of their target genes. Thus, RNAs containing the nucleoside analogues are promising candidates as photo-cross-linking probes to identify the target mRNAs of miRNAs.

  • Diazirine-Containing RNA Photo-Cross-Linking Probes for Capturing microRNA Targets
    2014
    Co-Authors: Kosuke Nakamoto, Yoshihito Ueno
    Abstract:

    Here, we report the applicability of diazirine-containing RNA photo-cross-linking probes for the identification of microRNA (miRNA) targets. The RNA cross-linking probes were synthesized by substituting the RNA nucleobases with nucleoside analogues such as 1-O-[3-(3-trifluoromethyl-3H-diazirin-3-yl)]­benzyl-β-d-ribofuranose or 1-O-[4-(3-trifluoromethyl-3H-diazirin-3-yl)]­benzyl-β-d-ribofuranose that carry aryl trifluoromethyl diazirine moieties. The probes were successfully cross-linked with synthetic RNAs containing the four natural nucleosides on the opposite site of the nucleoside analogues. Furthermore, it was found that miRNAs containing these analogues were effective in regulating the expression of their target genes. Thus, RNAs containing the nucleoside analogues are promising candidates as photo-cross-linking probes to identify the target mRNAs of miRNAs