Protein-mediated dethreading of a biotin-functionalised pseudorotaxane

In this article, we describe the synthesis of new biotin-functionalised naphthalene derivatives 3 and 4 and their complexation behaviour with avidin and neutravidin using a range of analytical techniques. We have shown using 2-(4prime or minute-hydroxyazobenzene)benzoic acid displacement and ITC experiments{,} that compounds 3 and 4 have the propensity to form reasonably high-affinity bioconjugates with avidin and neutravidin. We have also demonstrated using 1H NMR{,} UV-vis and fluorescence spectroscopy that the naphthalene moiety of 3 and 4 facilitates the formation of pseudorotaxane-like structures with 1 in water. We have then investigated the ability of avidin and neutravidin to modulate the complexation between 1 and 3 or 4. UV-vis and fluorescence spectroscopy has shown that in both cases the addition of the protein disrupts complexation between the naphthalene moieties of 3 and 4 with 1

A triple carboxylic acid-functionalized RAFT agent platform for the elaboration of well-defined telechelic 3-arm star PDMAc

This communication describes the synthesis of a triple acid-functionalized RAFT agent and its use to prepare well-defined 3-arm star polymers of N,N-dimethylacrylamide (DMAc). A simple esterification reaction allowed the convenient integration of three electron-rich naphthalene recognition units on the RAFT agent platform and subsequently the elaboration of a naphthalene end-decorated telechelic 3-arm star PDMAc. This functionalized star polymer was further exploited to build a hydrogel with a complementary homoditopic host unit featuring tetracationic macrocycle cyclobis(paraquat-p-phenylene) units

Immobilization of fluorescent chemosensor on pyrogenic silica: A promising device for gaseous detection

International audienceA new approach to enhance performances of a cyclodextrin-based fluorescent chemosensor combining grafting on a silica matrix and quaternization reaction is presented. The full characterization of new fluorescent hybrid material has clearly revealed the embedding of cyclodextrin inside the siliceous material. Finally, through a comparison with previous aqueous studies, a preliminary test of toluene detection was presented and highlighted the high potential of this approach, which opens attractive perspectives of evolution toward more sensitive and selective VOC's sensing in air or in hot industrial gaseous waste

«Aqueous Organometallic Catalysis: Contribution of CD-Based Hydrogels and CD-Substituted Polymers»

International audienceno abstrac

«Pickering Emulsions from CD-Based Hydrogels and CD-Substituted Polymers: Application to Aqueous Organometallic Catalysis»

International audienceno abstrac

«Multivalency in aqueous organometallic catalysis: Contribution of cyclodextrin-based polymers»

International audienceno abstrac

Internal structure investigation of pyrogenic modified silica by fluorescent labeling

International audienceWe present our recent investigation on the internal structure of hybrid materials based on pyrogenic chlorobenzylated silica obtained by classical heating and sonochemistry. A fluorescent labelling by the alkoxypyridylindolizine derivative was carried out by linking the chlorobenzyl pattern, of the native hybrid materials, by quaternization of the free pyridyl group contained in the fluorescent unit. The two fluorescent materials were characterized by InfraRed spectroscopy, Solid-state 13C NMR, Thermal analysis, SEM and the structural parameters were determined from the nitrogen's isotherm sorption using BET method and BJH model. It is shown that the fluorescence properties depend of the internal structure of materials and, consequently, of the synthesis methodology. So, the thermic way has furnished an open porous system while the sonochemical method's has led to a more closed porous system

Synthesis of a polypseudorotaxane, polyrotaxane, and polycatenane using \u27click\u27 chemistry

A study of the in vitro nanoparticle-templated assembly of a mutant of cowpea chlorotic mottle virus lacking most of the N-terminal domain (residues 4-37), NDelta34, is presented. Mutant empty proteins assemble into empty capsids with a much broader distribution of sizes than the wild-type virus. This increased flexibility in the assembly outcomes is known to be detrimental for the assembly process in the presence of molecular polyanions. However, when rigid polyanionic cores are used, such as nanoparticles, the assembly process is restored and virus-like particles form. Moreover, the breadth of the nanoparticle-templated capsid size distribution becomes comparable with the wild-type virus size distribution