Person:
Benito Peña, María Elena

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First Name
María Elena
Last Name
Benito Peña
URI
https://hdl.handle.net/20.500.14352/76070
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Analítica
Area
Química Analítica
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Author: Descalzo López, Ana Belén × End date: 2019 ×

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Now showing 1 - 3 of 3
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    Project number: 253
    Material docente interactivo en inglés para la enseñanza práctica y el autoaprendizaje de (bio)sensores químicos ópticos en Grado y Máster
    (2018) Descalzo López, Ana Belén; Orellana Moraleda, Guillermo; Moreno Bondi, María Cruz; Benito Peña, María Elena; Urraca Ruiz, Javier
    Material docente (guiones de prácticas, vídeos, cuestionarios multi-respuesta) en inglés para asignaturas de Grado y Máster relacionadas con el tema de sensores (bio)químicos ópticos y la preparación de nanomateriales aplicados en sensores ópticos
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    Highly fluorescent magnetic nanobeads with a remarkable stokes shift as labels for enhanced detection in immunoassays
    (Small, 2018) Salis, Francesca; Descalzo López, Ana Belén; Benito Peña, María Elena; Moreno Bondi, María Cruz; Orellana Moraleda, Guillermo
    Fluorescence immunoassays are popular for achieving high sensitivity, but they display limitations in biological samples due to strong absorption of light, background fluorescence from matrix components, or light scattering by the biomacromolecules. A powerful strategy to overcome these problems is introduced here by using fluorescent magnetic nanobeads doped with two boron-dipyrromethane dyes displaying intense emission in the visible and near-infrared regions, respectively. Careful matching of the emission and absorption features of the dopants leads to a virtual Stokes shift larger than 150 nm achieved by an intraparticle Förster resonance energy transfer (FRET) process between the donor and the acceptor dyes. Additionally, the magnetic properties of the fluorescent beads allow preconcentration of the sample. To illustrate the usefulness of this approach to increase the sensitivity of fluorescence immunoassays, the novel nanoparticles are employed as labels for quantification of the widely used Tacrolimus (FK506) immunosuppressive drug. The FRET-based competitive inhibition immunoassay yields a limit of detection (LOD) of 0.08 ng/mL, with a dynamic range (DR) of 0.15–2.0 ng/mL, compared to a LOD of 2.7 ng/mL and a DR between 4.1 and 130 ng/mL for the immunoassay carried out with direct excitation of the acceptor dye.
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    Sensitive rapid fluorescence polarization immunoassay for free mycophenolic acid determination in human serum and plasma
    (Analytical Chemistry, 2018) Glahn Martínez, Ana Bettina; Benito Peña, María Elena; Salis, Francesca; Descalzo López, Ana Belén; Orellana Moraleda, Guillermo; Moreno Bondi, María Cruz
    In this Article, we describe a fluorescence polarization immunoassay (FPIA) using a new label-near infrared fluorescent dye. The developed FPIA method was optimized for the rapid analysis of free mycophenolic acid (MPA) in plasma of transplanted patients. The approach is based on the fluorescence competitive assay between the target immunosuppressant and a novel emissive near-infrared fluorescent dye-tagged MPA and MPA-AO for the binding sites of the anti-MPA antibody. The fluorescent analogue of MPA exhibits emission at 654 nm upon excitation at 629 nm (λexcmax) and shows a good photochemical stability and a significant emission quantum yield (0.16) in phosphate buffer media. Free mycophenolic acid was isolated from blood or plasma samples using ultrafiltration prior to analysis. The sample was incubated for 20 min with 5 μg/mL of anti-MPA antibody and 1 nM of MPA-AO before the measurements. The developed FPIA displays a limit of detection of 0.8 ng/mL (10% binding inhibition) and a dynamic range of 1.7−39 ng/mL (20%−80% binding inhibition) in a PBST buffer, fitting the therapeutic requirements. The immunoassay selectivity was evaluated by measuring the cross-reactivity to other immunosuppressive drugs administered in combination with MPA (cyclosporin A and tacrolimus), as well as for the metabolite MPA glucuronide. The assay has been successfully applied to the analysis of free MPA in the blood of a heart-transplanted patient after oral administration of both mycophenolate mofetil (MMF) and tacrolimus, and the results have been compared with those obtained by rapid-resolution liquid chromatography with diode array detection (RRLC-DAD).