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Chirality has been used as an internal probe of structural changes accompanying micro‐aggregation of a soluble regioregular poly(alkylthiophene). First, the synthesis of new polythiophenes having long alkyl chains is described. The UV/vis and circular dichroic spectroscopy are shown to indicate that the transformation of a disordered species in solution into an ordered one in a micro‐aggregated state is a two‐step process. Tentative proposals are made about the nature of the intermediate state, which, however, remains unclear.

A series of head to tail alkyl-substituted oligothiophenes was synthesized by a stepwise synthesis based on the repetitive use of the Suzuki coupling reaction between a stable thienyl boronic ester and the appropriate chloride-protected precursors catalyzed by Pd[P(C6H5)3]4, under mild conditions. By this method, a very high level of regiospecificity was achieved, as shown in the synthesis of the dimer 3,4‘-dioctyl-5‘-chloro-2,2‘-bithiophene, where no regioisomers could be detected. From the thus obtained chlorinated oligomers, free-ends oligo(3-octylthiophenes) were synthesized by reductive dehalogenation. UV−visible properties were investigated in solution, and the absorption energy was found to depend linearly on the reciprocal of the number of thiophene units. A comparison with the properties of analogous regioregular poly(3-octylthiophenes) gave information on the structure of such polymers in solution.

A new methodology for the preparation of addressed DNA matrices is described. The process includes an electrochemically directed copolymerization of pyrrole and oligonucleotides bearing on their 5' end a pyrrole moiety introduced by phosphoramidite chemistry. The electro-controlled synthesis of the copolymer (poly-pyrrole) gives, in one step, a solid conducting film deposited on the surface of an electrode. The resulting polymer consists of pyrrole chains bearing covalently linked oligonucleotide. The polymer growth is limited to the electrode surface, so that it is possible to prepare a DNA matrix on a multiple electrode device by successive copolymerizations. A support bearing four oligonucleotides was used to detect three ras mutations on a synthetic DNA fragment.

We describe in this paper a methodology to quantify multispot parallel DNA hybridizations and denaturations on gold surfaces by using, on one hand, a polypyrrole-based surface functionalization based on an electrospotting process and, on the other hand, surface plasmon resonance imaging allowing real-time measurements on several DNA spots at a time. Two characterization steps were performed in order to optimize the immobilization of oligonucleotide probes and, thus, to increase the signal-to-noise ratio of monitored hybridization signals: the first step consisted of characterizing the signal dependence upon the density of immobilized 15-mer probes, and, the second step, in analyzing the hybridization response versus spot thickness. We further demonstrated that a surface density of polypyrrole/DNA probes of approximately 130 fmol/ mm2 (590 pg/mm2) optimizes the hybridization signal that can be detected directly. Optimal thickness of the spot was found to be close to 11 nm. Specificity and regeneration steps on each spot have also been demonstrated successfully, showing this method to be very competitive and convenient in use.

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Building of hierarchical core-shell hetero-structures is currently the subject of intensive research in the electrochemical field owing to its potential for making improved electrodes for high-performance micro-supercapacitors. Here we report a novel architecture design of hierarchical MnO2@silicon nanowires (MnO2@SiNWs) hetero-structures directly supported onto silicon wafer coupled with Li-ion doped 1-Methyl-1-propylpyrrolidinium bis(trifluromethylsulfonyl)imide (PMPyrrBTA) ionic liquids as electrolyte for micro-supercapacitors. A unique 3D mesoporous MnO2@SiNWs in Li-ion doped IL electrolyte can be cycled reversibly across a voltage of 2.2 V and exhibits a high areal capacitance of 13 mFcm−2. The high conductivity of the SiNWs arrays combined with the large surface area of ultrathin MnO2 nanoflakes are responsible for the remarkable performance of these MnO2@SiNWs hetero-structures which exhibit high energy density and excellent cycling stability. This combination of hybrid electrode and hybrid electrolyte opens up a novel avenue to design electrode materials for high-performance micro-supercapacitors.