2'-F labelling of ribose in RNAs: a tool to analyse RNA/protein interactions by NMR in physiological conditions.

Protein-RNA interactions are central to numerous cellular processes. In this work, we present an easy and straightforward NMR-based approach to determine the RNA binding site of RNA binding proteins and to evaluate the binding of pairs of proteins to a single-stranded RNA (ssRNA) under physiological conditions, in this case in nuclear extracts. By incorporation of a F atom on the ribose of different nucleotides along the ssRNA sequence, we show that, upon addition of an RNA binding protein, the intensity of the F NMR signal changes when the F atom is located near the protein binding site.

Surface Passivation with a Perfluoroalkane Brush Improves the Precision of Single-Molecule Measurements.

Single-molecule imaging is invaluable for investigating the heterogeneous behavior and interactions of biological molecules. However, an impediment to precise sampling of single molecules is the irreversible adsorption of components onto the surfaces of cover glasses. This causes continuous changes in the concentrations of different molecules dissolved or suspended in the aqueous phase from the moment a sample is dispensed, which will shift, over time, the position of chemical equilibria between monomeric and multimeric components.

Facile Strategy for the Synthesis of Gold@Silica Hybrid Nanoparticles with Controlled Porosity and Janus Morphology.

Hybrid materials prepared by encapsulation of plasmonic nanoparticles in porous silica systems are of increasing interest due to their high chemical stability and applications in optics, catalysis and biological sensing. Particularly promising is the possibility of obtaining gold@silica nanoparticles (Au@SiO₂ NPs) with Janus morphology, as the induced anisotropy can be further exploited to achieve selectivity and directionality in physical interactions and chemical reactivity. However, current methods to realise such systems rely on the use of complex procedures based on binary solvent mixtures and varying concentrations of precursors and reaction conditions, with reproducibility limited to specific Au@SiO₂ NP types.

Mesoscopic FRET Antenna Materials by Self-Assembling Iridium(III) Complexes and BODIPY Dyes.

This study presents a new design of light-harvesting antenna materials using two dyes organised into mesoporous silica: an iridium(III) complex and a BODIPY-derived surfactant that undergo Förster resonance energy transfer (FRET), acting, respectively, as donor and acceptor. The chemical structure of each dye determines the position taken within the micellar templates used for the synthesis of the silica host, which maintains mesopore order as shown by TEM imaging. Steady-state and time-resolved UV-visible spectroscopy revealed that incorporation of the iridium complex into the silica shields it from oxygen-induced quenching and allows a degree of control over the donor-acceptor distance, yielding FRET efficiencies from 24 to 76 % and tuneable emission ranges.