Person:
Valverde De La Fuente, Alejandro

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First Name
Alejandro
Last Name
Valverde De La Fuente
URI
https://hdl.handle.net/20.500.14352/86280
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Analítica
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2018 - 20193
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Author: Pingarrón Carrazón, José Manuel ×

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Now showing 1 - 3 of 3
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    Versatile electroanalytical bioplatforms for dimultaneous determination of cancer-related DNA 5-hethyl- and 5-hydroxymethyl-cytosines at global and gene-specific levels in human serum and tissues
    (ACS Sensors, 2018) Povedano Muñumel, Eloy; Ruiz Valdepeñas Montiel, Víctor; Valverde De La Fuente, Alejandro; Navarro Villoslada, Fernando; Yáñez-Sedeño Orive, Paloma; Pedrero Muñoz, María; Montero-Calle, Ana; Barderas Manchado, Rodrigo; Peláez-García, Alberto; Mendiola, Marta; Hardisson, David; Feliú, Jaime; Camps, Jordi; Rodríguez-Tomàs, Elisabet; Joven, Jorge; Arenas, Meritxell; Campuzano Ruiz, Susana; Pingarrón Carrazón, José Manuel
    This paper reports the preparation of versatile electrochemical biosensing platforms for the simple, rapid, and PCR-independent detection of the most frequent DNA methylation marks (5-methylcytosine, 5-mC, and/or 5-hydroxymethylcytosine, 5-hmC) both at global and gene-specific levels. The implemented strategies, relying on the smart coupling of immuno-magnetic beads (MBs), specific DNA probes and amperometric detection at screen-printed carbon electrodes (SPCEs), provided sensitive and selective determination of the target methylated DNAs in less than 90 min with a great reproducibility and demonstrated feasibility for the simultaneous detection of the same or different cytosine epimarks both at global level and in different loci of the same gene or in different genes. The bioplatforms were applied to determine global methylation events in paraffin-embedded colorectal tissues and specific methylation at promoters of tumor suppressor genes in genomic DNA extracted from cancer cells and paraffin-embedded colorectal tissues, and in serum without previous DNA extraction from cancer patients.
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    Simultaneous amperometric immunosensing of the metastasis-related biomarkers IL-13Rα2 and CDH-17 by using grafted screen-printed electrodes and a composite prepared from quantum dots and carbon nanotubes for signal amplification
    (Microchimica Acta, 2019) Serafín González-Carrato, Verónica; Valverde De La Fuente, Alejandro; Garranzo-Asensio, María; Barderas, Rodrigo; Campuzano Ruiz, Susana; Yáñez-Sedeño Orive, Paloma; Pingarrón Carrazón, José Manuel
    This paper describes a dual electrochemical immunoassay for the simultaneous determination of IL-13Rα2 and CDH-17, two biomarkers of emerging relevance in metastatic processes. The sandwich assay uses a screen-printed dual carbon electrode that was electrochemically grafted with p-aminobenzoic acid to allow the covalent immobilization of capture antibodies. A hybrid composed of graphene quantum dots (GQDs) and multiwalled carbon nanotubes (MWCNTs) act as nanocarriers for the detection antibodies and horseradish peroxidase. The use of this hybrid material considerably improves the assay (in comparison to the use of MWCNTs) due to the peroxidase mimicking activity of the GQDs. The method works at a low working potential (0.20 V vs. Ag pseudo-reference electrode) and thus is not readily interfered by unknown electroactive species. The dual immunoassay allows for the selective determination of both biomarkers with LOD values of 1.4 (IL-13sRα2) and 0.03 ng mL-1 (CDH-17). The simultaneous determination of IL-13Rα2 and CDH-17 was accomplished in lysates from breast and colorectal cancer cells with different metastatic potential, and in paraffin-embedded tumor tissues extracts from patients diagnosed with colorectal cancer at different stages. The applicability to discriminate the metastatic potential even in intact cells through the detection of both extracellular receptors has been demonstrated also. The assay can be performed within 3 h, requires small sample amounts (0.5 μg), and has a simple protocol. Graphical abstract Dual amperometric immunosensing of the metastasis-related biomarkers IL-13Rα2 and CDH-17 in human colorectal cancer cells and tissues by using grafted screen-printed electrodes and composites of quantum dots and carbon nanotubes as nanocarriers.
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    Graphene quantum dots-functionalized multi-walled carbon nanotubes as nanocarriers in electrochemical immunosensing. Determination of IL-13 receptor α2 in colorectal cells and tumor tissues with different metastatic potential
    (Sensors and Actuators B: Chemical, 2019) Serafín González-Carrato, Verónica; Valverde De La Fuente, Alejandro; Martínez-García, Gonzalo; Martínez-Periñán, Emiliano; Comba, Fausto; Garranzo-Asensio, María; Barderas, Rodrigo; Yáñez-Sedeño Orive, Paloma; Campuzano Ruiz, Susana; Pingarrón Carrazón, José Manuel
    In this work, the development of the first integrated electrochemical immunosensor for the determination of the IL-13Rα2 is reported. The strategy involves the immobilization of a biotinylated capture antibody onto streptavidin-modified screen-printed electrodes through grafting with p-aminobezoic acid (p-ABA) and further activation using EDC/Sulfo-NHS chemistry. A hybrid nanomaterial composed of multiwalled carbon nanotubes (MWCNTs) and Graphene Quantum Dots (GQDs) was used as nanocarrier of multiple detector antibody and HRP molecules. Amperometric detection with the system H2O2/hydroquinone (HQ) achieved a linear calibration plot ranging from 2.7 to 100 ng mL−1 IL-13sRα2, with a LOD value of 0.8 ng mL−1. The immunosensor showed an excellent selectivity and was successfully applied to the determination of the target receptor directly in small amounts of raw cellular lysates and extracts of paraffin-embedded tissues from patients diagnosed with colorectal cancer at different stages.