Person:
Glahn Martínez, Ana Bettina

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First Name
Ana Bettina
Last Name
Glahn Martínez
URI
https://hdl.handle.net/20.500.14352/85707
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Analítica
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End date: 2019 × Start date: 2018 ×

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Now showing 1 - 2 of 2
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    Optical Biosensors for Label-Free Detection of Small Molecules
    (Sensors, 2018) Peltomaa, Riikka Johanna; Glahn Martínez, Ana Bettina; Benito Peña, María Elena; Moreno Bondi, María Cruz
    Label-free optical biosensors are an intriguing option for the analyses of many analytes, as they offer several advantages such as high sensitivity, direct and real-time measurement in addition to multiplexing capabilities. However, development of label-free optical biosensors for small molecules can be challenging as most of them are not naturally chromogenic or fluorescent, and in some cases, the sensor response is related to the size of the analyte. To overcome some of the limitations associated with the analysis of biologically, pharmacologically, or environmentally relevant compounds of low molecular weight, recent advances in the field have improved the detection of these analytes using outstanding methodology, instrumentation, recognition elements, or immobilization strategies. In this review, we aim to introduce some of the latest developments in the field of label-free optical biosensors with the focus on applications with novel innovations to overcome the challenges related to small molecule detection. Optical label-free methods with different transduction schemes, including evanescent wave and optical fiber sensors, surface plasmon resonance, surface-enhanced Raman spectroscopy, and interferometry, using various biorecognition elements, such as antibodies, aptamers, enzymes, and bioinspired molecularly imprinted polymers, are reviewed.
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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).