Polydipyrrole- and polydicarbazole-nanorods as new nanosized supports for DNA hybridization

Novel functional polydipyrrole- and polydicarbazole nanorods have been AAO template-synthesized from COOH-dipyrrole/-dicarbazole monomers using Vapor Deposition and Liquid Phase Polymerizations (VDP and LPP). They were tested as insoluble supports for covalent DNA attachment and hybridization.     

A Simple Homemade Reaction Station for use in Parallel Solution-Phase Synthesis. Optimization of a Regioselective One-Step Deprotective o-formylation Reaction Mediated by the Vilsmeier-Haack Reagent POCl3⋅DMF

Summary We report herein the fabrication of a simple and price-affordable portable reaction station for use in parallel solution-phase synthesis. This homemade device uses currently available laboratory components and equipment. Specifically designed to fit standard magnetic hotplates/stirrers, it can simultaneously hold up to 24 heated and magnetically stirred glass reactors of both 10 and 50 mL capacities. Glass reactors are connected by flexible 16-gauge metal needles to a central gas manifold equipped with an inlet/outlet for vacuum and inert gases. Reaction temperatures can be optimally varied from −78 ^∘C to 150 ^∘C. Using a statistical screening DOE method, this parallel array reactor station has been successfully operated to optimize the one-step deprotective O-formylation of a sterically hindered bis-O-tert-butyldiphenylsilyl (O-TBDPS) aromatic diol. The latter transformation was mediated by the Vilsmeier-Haack reagent POCl₃⋅DMF using a range of Lewis acid and metal salt promoters, including their binary combinations.     

Preparation of novel photoreactive polycarbazole‐based microparticles: Reactivity features

Four types of innovative benzophenone (BPh)‐ or aryl azide (ArAz)‐containing photoreactive polycarbazole (polyCbz)‐based microparticles (MPs) were prepared using an oxidative liquid phase polymerization system. Their photochemical reactivity was evaluated by their reaction with highly inert poly(2‐chloro‐paraxylelene) (Parylene C) films. Possible mechanisms for the photochemical reaction of those MPs with Parylene C were discussed. The highly photoreactive BPh was found to react more inside the particle causing internal cross‐linking of MP polyCbz chains, fusion between adjoining particles and deformation of their spherical structure. In contrast, the less reactive but more selective ArAz‐containing MPs were found to react much more with Parylene C. The strong reactivity of such photoreactive MPs toward Parylene C films emphasizes a general method for the functionalization of stable nonfunctional polymeric coatings. This paves the way to simple and solvent‐free functionalization of nonfunctional coatings and materials by light. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

New magnetically responsive polydicarbazole-magnetite nanoparticles

Magnetically responsive COOH-polydicarbazole-magnetite nanocomposites have been prepared by chemical oxidation of three COOH-dicarbazole monomers and - in the presence of magnetite nanoparticles. These functionalized nanoparticles have been tested for DNA hybridization experiments.     

Sonochemical Coatings of ZnO and CuO Nanoparticles Inhibit Streptococcus mutans Biofilm Formation on Teeth Model

Antibiotic resistance has prompted the search for new agents that can inhibit bacterial growth. We recently reported on the antibiofilm activities of nanosized ZnO and CuO nanoparticles (NPs) synthesized by using sonochemical irradiation. In this study, we examined the antibacterial activity of ZnO and CuO NPs in a powder form and also examined the antibiofilm behavior of teeth surfaces that were coated with ZnO and CuO NPs using sonochemistry. Free ZnO and CuO NPs inhibited biofilm formation of Streptococcus mutans . Furthermore, by using the sonochemical procedure, we were able to coat teeth surfaces that inhibited bacterial colonization.     

Towards hybrid carbazole/pyrrole-based carboxylated monomers: chemical synthesis, characterisation and electro-oxidation properties

Six novel hybrid carbazole (Cbz)-pyrrole (Pyr)-based carboxylated monomers were synthesised and unambiguously characterised using common spectroscopic tools. Clauson-Kaas, amide coupling, LAH (lithium aluminium hydride)-mediated reduction, esterification and debenzylation reactions were used as key chemical reactions towards their multi-step synthesis. The electro-oxidation features of all these six hybrid Cbz/Pyr-monomers were investigated for the electro-deposition of corresponding polyCOOH conducting coatings. Quite interestingly, and due to the fact that such electro-oxidisable monomers contain both types of oxidisable heterocycles, that is, Pyr and Cbz species, it was found that the successful electro-polymerisation of these hybrid Cbz/Pyr-monomers was highly dependent on the relative number of Cbz versus Pyr unit(s) present in corresponding monomers. Indeed, a successful electro-deposition of the corresponding conducting polymeric films onto a working Pt electrode was observed only for hybrid monomers characterised by a Cbz/Pyr unit(s) ratio greater than or equal to 1. This result has been validated by systematically tuning the number of oxidisable Cbz and Pyr unit(s) present in monomers through proper chemical design and monomer multi-step synthesis. In that case, cyclic voltammogram analyses readily confirmed the exclusive electro-deposition of conductingpolyCbz-films.