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Nickel(II) β-azido-meso-tetraphenylporphyrin was successfully anchored on silicon using a bifunctional linker that bears two terminal alkyne functions by the sequence (i) hydrosilylation of a C=C triple bond of the linker by surface Si-H groups and (ii) 1,3-Huisgen cycloaddition between the alkyne-terminated silicon surface and the azidoporphyrin derivative. [ABSTRACT FROM AUTHOR]

Nickel(ii) β-azido-meso-tetraphenylporphyrin was successfully anchored on silicon using a bifunctional linker that bears two terminal alkyne functions by the sequence (i) hydrosilylation of a CC triple bond of the linker by surface Si–H groups and (ii) 1,3-Huisgen cycloaddition between the alkyne-terminated silicon surface and the azidoporphyrin derivative. [ABSTRACT FROM AUTHOR]

Determining the affinity of proteins for uranyl is key to understand the toxicity of this cation and to further develop decorporation strategies. However, usual techniques to achieve that goal often require specific equipment and expertise. Here, we propose a simple, efficient, fluorescence-based method to assess the affinity of proteins and peptides for uranyl, at equilibrium and in buffered solution. We first designed and characterized an original uranyl-binding fluorescent probe. We then built a reference scale for uranyl affinity in solution, relying on signal quenching of our fluorescent probe in presence of high-affinity uranyl-binding peptides. We finally validated our approach by re-evaluating the uranyl-binding affinity of four native proteins. We envision that this tool will facilitate the reliable and reproducible assessment of affinities of peptides and proteins for uranyl., (© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Silicon nanoparticles (NPs) serve a wide range of optical, electronic, and biological applications. Chemical grafting of various molecules to Si NPs can help to passivate their reactive surfaces, "fine-tune" their properties, or even give them further interesting features. In this work, (1) H, (13) C, and (29) Si solid-state NMR spectroscopy has been combined with density functional theory calculations to study the surface chemistry of hydride-terminated and alkyl-functionalized Si NPs. This combination of techniques yields assignments for the observed chemical shifts, including the contributions resulting from different surface planes, and highlights the presence of physisorbed water. Resonances from near-surface (13) C nuclei were shown to be substantially broadened due to surface disorder and it is demonstrated that in an ambient environment hydride-terminated Si NPs undergo fast back-bond oxidation, whereas long-chain alkyl-functionalized Si NPs undergo slow oxidation. Furthermore, the combination of NMR spectroscopy and DFT calculations showed that the employed hydrosilylation reaction involves anti-Markovnikov addition of the 1-alkene to the surface of the Si NPs., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Magic-angle spinning dynamic nuclear polarization (MAS-DNP) has been proven to be a powerful technique to enhance the sensitivity of solid-state NMR (SSNMR) in a wide range of systems. Here, we show that DNP can be used to polarize lipids using a lipid-anchored polarizing agent. More specifically, we introduce a C16-functionalized biradical, which allows localization of the polarizing agents in the lipid bilayer and DNP experiments to be performed in the absence of excess cryo-protectant molecules (glycerol, dimethyl sulfoxide, etc.). This constitutes another original example of the matrix-free DNP approach that we recently introduced., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Peptides are interesting tools to rationalize uranyl-protein interactions, which are relevant to uranium toxicity in vivo. Structured cyclic peptide scaffolds were chosen as promising candidates to coordinate uranyl thanks to four amino acid side chains pre-oriented towards the dioxo cation equatorial plane. The binding of uranyl by a series of decapeptides has been investigated with complementary analytical and spectroscopic methods to determine the key parameters for the formation of stable uranyl-peptide complexes. The molar ellipticity of the uranyl complex at 195 nm is directly correlated to its stability, which demonstrates that the β-sheet structure is optimal for high stability in the peptide series. Cyclodecapeptides with four glutamate residues exhibit the highest affinities for uranyl with log KC =8.0-8.4 and, therefore, appear as good starting points for the design of high-affinity uranyl-chelating peptides., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Nickel(II) beta-azido-meso-tetraphenylporphyrin was successfully anchored on silicon using a bifunctional linker that bears two terminal alkyne functions by the sequence (i) hydrosilylation of a C[triple bond]C triple bond of the linker by surface Si-H groups and (ii) 1,3-Huisgen cycloaddition between the alkyne-terminated silicon surface and the azidoporphyrin derivative.