No abstract

We present here the synthesis and structural characterization of hybrid Au-polypyrrole-Au and Ptpolypyrrole-Au nanowires together with a study of their electrical properties from room-temperature down to very low temperature. A careful characterization of the metal-polymer interfaces by transmission electron microscopy revealed that the structure and mechanical strength of bottom and upper interfaces are very different. Variable temperature electrical transport measurements were performed on both multiple nanowires -contained within the polycarbonate template -and single nanowires. Our data show that the three-dimensional Mott variable-range-hopping model provides a complete framework for the understanding of transport in PPy nanowires, including non-linear current-voltage characteristics and magnetotransport at low temperatures. † Research associate of the FNRS. ometry of the devices. Despite these experimental efforts, the electrical transport at nanoscale in conjugated polymers is still matter of debate. Until now, very few studies [4,9] focused on the synthesis and electrical characterization of hybrid conjugated polymer-metal nanowires. Moreover, none of them reported on the structural characterization of the metal-polymer interfaces, which could play an important role on the electrical properties of the nanodevices. We present here the synthesis and structural characterization of hybrid metal(Au or Pt)-polypyrrole(PPy)-metal(Au) nanowires together with a study of their electrical properties from roomtemperature down to very low temperature (T ≈ 0.5 K). Metallic segments, few microns long, serving as contacting electrodes are electrochemically synthetized within polycarbonate (PC) templates, before and after the PPy nanowire growth. Interestingly, the resulting metal-PPymetal hybrid nanowires have two morphologically different PPy-metal interfaces (see Fig. 1). In terms of mechanical robustness the PPy-onto-metal interface is smoother and more fragile than the metal-onto-PPy interface. By using Pt instead of Au for the first grown segment, much more robust nanowires have been fabricated. The present all-electrochemical technique allows controlled optimization of the mechanical strength arXiv:1112.4656v1 [cond-mat.mes-hall]

Selective voltammetric sensing of ATP(2-) anions in water was achieved using ferrocene-viologen based redox active receptors and related polymer films.

International audienceBy virtue of strong ion-paring interactions that are reinforced following oxidation of ferrocene moieties to ferrocenium form, films synthesized by oxidative polymerization of pyrrole-containing (ferrocenylmethyl)trialkylammonium cations are able to electrochemically sense the dihydrogenphosphate anion in organic electrolytes. Strong and selective affinity of these cationic polymer films towards H₂PO₄^- was evidenced from FT-IR and EQCM experiments. Clear two-wave differential pulse voltammetry features allow the amperometric titration of this anion