Synthesis and Electrochemical Characterization of Poly(2-methoxy-4-vinylphenol) with MWCNTs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The present work describes a simple grafting of poly-2-methoxy-4-vinylphenol to multiwalled carbon nanotubes (MWCNTs) by in situ free radical polymerization. The synthesis was performed using mild conditions and the product (MWCNTs/pMVP) was stable for at least 6 months. Also, the dispersion of the MWCNTs/pMVP in dimethyl-formamide remained homogeneously distributed for up to 2 days, facilitating the modification of glassy carbon electrode. After an in situ activation process, the stable redox couple was formed (catechol/quinone) being able to electrocatalyze NADH oxidation at low overpotential with a high rate constant (k(obs)).231125622568Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Construction of a new functional platform by grafting poly(4-vinylpyridine) in multi-walled carbon nanotubes for complexing copper ions aiming the amperometric detection of L-cysteine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This work describes the preparation of an amperometric sensor for electrocatalytical detection of L-cysteine (Cys). The developed sensor is based on a functional platform to complex copper ions on multi-walled carbon nanotubes (MWCNTs) modified with poly-4-vinylpyridine (PVP) through an in situ polymerization. The obtained values for the kinetic constants of heterogeneous electron transfer rate (k(s)) and for chemical reaction (k(obs)) between Cu2+ and cysteine were 5.78 s(-1) and 6.96 L mol(-1) s(-1), respectively. The analytical curve showed a linear response range for detecting L-cysteine in concentrations from 5 to 60 mu mol L-1. The detection and quantification limits obtained were 1.50 and 5.00 mu mol L-1, respectively with a response time of 0.10 s at an applied potential of 150 mV vs SCE. (C) 2012 Elsevier Ltd. All rights reserved.71150158Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Measurement of the B-s(0) ->mu(+)mu(-) Branching Fraction and Search for B-0 -> mu(+)mu(-) with the CMS Experiment

Results are presented from a search for the rare decays B-s(0) -> mu(+) mu(-) and B-0 -> mu(+) mu(-) in pp collisions at root s = 7 and 8 TeV, with data samples corresponding to integrated luminosities of 5 and 20 fb(-1), respectively, collected by the CMS experiment at the LHC. An unbinned maximum-likelihood fit to the dimuon invariant mass distribution gives a branching fraction 'B(B-s(0) -> mu(+)mu(-)) = (3.0(-0.9)(+1.0)) x 10(-9), where the uncertainty includes both statistical and systematic contributions. An excess of B-s(0) -> mu(+)mu(-) events with respect to background is observed with a significance of 4.3 standard deviations. For the decay B-0 -> mu(+)mu(-) an upper limit of 'B(B-0 -> mu(+) mu(-)) < 1.1 x 10(-9) at the 95% confidence level is determined. Both results are in agreement with the expectations from the standard model