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Jambois O.,University of Barcelona | Gourbilleau F.,CNRS Center for Research on Ions, Materials and Photonics | Kenyon A.J.,University College London | Montserrat J.,Institute Microelectronica Of Barcelona Imb Cnm | And 2 more authors.
Optics Express | Year: 2010

This study reports the estimation of the inverted Er fraction in a system of Er doped silicon oxide sensitized by Si nanoclusters, made by magnetron sputtering. Electroluminescence was obtained from the sensitized erbium, with a power efficiency of 10-2%. By estimating the density of Er ions that are in the first excited state, we find that up to 20% of the total Er concentration is inverted in the best device, which is one order of magnitude higher than that achieved by optical pumping of similar materials. ©2009 Optical Society of America.

De La Rica R.,CUNY - Hunter College | Mendoza E.,Institute Microelectronica Of Barcelona Imb Cnm | Mendoza E.,Research Center on Nanoscience and Nanotechnology 2 CSIC | Matsui H.,CUNY - Hunter College
Small | Year: 2010

An ultralow concentration of Pb ions is detected by a sensor integrating a peptide nanotube detection platform with a smart peptide function that specifically metalizes the target ion. As the PbII-binding peptide on the nanotube, which bridges two electrodes, templates Pb nanowires, a resistor appears in the circuit, and conductance is detected as the signal for PbII. © 2010 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim.

Baldrich E.,Institute Microelectronica Of Barcelona Imb Cnm
Methods in molecular biology (Clifton, N.J.) | Year: 2011

In less than 40 years, aptamers have consolidated their role in biosensor development. Chemically related to nucleic acid probes, production of aptamers against targets of various sizes and compositions places them as ideal capture elements, alternative to more consolidated molecules such as antibodies. Thanks to their chemical simplicity and production, as well as their unique characteristics, aptamers have been successfully integrated in several innovative approaches. The incorporation of aptamers into the existing microarray technologies has lead to the reporting of various detection strategies, including direct fluorescence detection of fluorescent reporters, fluorescence anisotropy, FRET, SPR imaging, and electrochemical detection.

Marshall J.E.,University of Cambridge | Ji Y.,University of Cambridge | Torras N.,Institute Microelectronica Of Barcelona Imb Cnm | Zinoviev K.,Institute Microelectronica Of Barcelona Imb Cnm | Terentjev E.M.,University of Cambridge
Soft Matter | Year: 2012

Liquid crystal elastomers (LCEs) are of considerable interest for their potential as actuators, due to the ability of aligned monodomain LCEs to reversibly change their bulk dimensions in response to a phase change. Many LCEs reported in the literature will contract in one dimension in response to a temperature change or irradiation with ultraviolet light. For practical applications, photo-actuation is a more useful technology than thermal actuation due to the achievable speed and localization of the response. The use of UV light sources to 'switch' the materials is impractical, however, due to considerations of both safety and cost. Sensitization of LCEs to light of higher wavelengths may be achieved by mixing a small concentration of carbon nanotubes (CNTs) into the polymer matrix; CNTs will absorb light over a large range of wavelengths, and convert it into local heat, thus triggering the required phase changes in the LCE. In this article we demonstrate that a low concentration of multi-walled CNTs does not affect the thermal response of the polymers but does significantly enhance their response to infra-red (IR) and visible light. © 2012 The Royal Society of Chemistry.

Ceto X.,Autonomous University of Barcelona | Gutierrez J.M.,CINVESTAV | Gutierrez M.,Institute Microelectronica Of Barcelona Imb Cnm | Cespedes F.,Autonomous University of Barcelona | And 4 more authors.
Analytica Chimica Acta | Year: 2012

This work reports the application of a voltammetric electronic tongue system (ET) made from an array of modified graphite-epoxy composites plus a gold microelectrode in the qualitative and quantitative analysis of polyphenols found in wine. Wine samples were analyzed using cyclic voltammetry without any sample pretreatment. The obtained responses were preprocessed employing discrete wavelet transform (DWT) in order to compress and extract significant features from the voltammetric signals, and the obtained approximation coefficients fed a multivariate calibration method (artificial neural network-ANN-or partial least squares-PLS-) which accomplished the quantification of total polyphenol content. External test subset samples results were compared with the ones obtained with the Folin-Ciocalteu (FC) method and UV absorbance polyphenol index (I280) as reference values, with highly significant correlation coefficients of 0.979 and 0.963 in the range from 50 to 2400mgL-1 gallic acid equivalents, respectively. In a separate experiment, qualitative discrimination of different polyphenols found in wine was also assessed by principal component analysis (PCA). © 2012 Elsevier B.V.

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