Person:
González Cortés, Araceli

First Name

Araceli

Last Name

González Cortés

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Químicas

Department

Química Analítica

Area

Química Analítica

Identifiers

Full item page

Search Results

Now showing 1 - 10 of 16

Determinación de plastificantes y antioxidantes mediante técnicas electroanalíticas en sistemas dispersos
(Universidad Complutense de Madrid, 1994) González Cortés, Araceli; Pingarrón Carrazón, José Manuel; Yáñez-Sedeño Orive, Paloma
Se ha realizado un estudio electroanalítico de los plastificantes: ftalato de dimetilo, de dietilo y de dibutilo, asi como de los antioxidantes 2-t-butil-4-metoxifenol (bha) y t-butihidroquinona (tbhq). Dada la escasa solubilidad en agua de estos aditivos, se han empleado como medios de trabajo disoluciones miscelares y emulsiones del tipo aceite-agua para desarrollar los métodos electroanalíticos. Una vez elegido el tensoactivo más adecuado para solubilizar cada analito, se han estudiado los procesos electródicos implicados, investigando el efecto del ph sobre la respuesta electroquímica y aplicando las técnicas y criterios habituales, con el fin de proponer, si ello es posible, los mecanismos de la reacción electroquímica implicada. Por último, se han establecido las características analíticas de los métodos desarrollados. En el medio emulsionado, la sistemática de trabajo ha sido análoga, si bien se ha elegido en primer lugar el disolvente orgánico adecuado para formar las emulsiones, optimizándose algunas variables experimentales de las mismas. los métodos desarrollados se han aplicado, finalmente, a la determinación de estos compuestos en muestras de alimentos, tales como leche, goma de mascar, aceites y palomitas de maíz, obteniéndose, en general, una mayor simplicidad en los procedimientos de preparación y tratamiento de la muestra debida a las características inherentes a los medios organizados empleados.
A disposable electrochemical immunosensor for the determination of leptin in serum and breast milk
(RSC, 2013) Ojeda, Irene; Moreno Guzmán, María; González Cortés, Araceli; Yáñez Sedeño, Paloma; Pingarrón Carrazón, José Manuel
The preparation of a disposable electrochemical immunosensor for the quantification of the hormone leptin is described in this work. The preparation approach involved immobilization of a specific biotinylated anti-leptin antibody on the surface of streptavidin-functionalized magnetic beads (StreptMBs) and a sandwich-type immunoassay involving the target analyte, monoclonal anti-leptin, and IgG labeled with alkaline phosphatase (AP-IgG). The electrochemical transduction step was accomplished by trapping the MBs bearing the immunoconjugates onto screen-printed carbon electrodes (SPCEs) by means of an Nd magnet and measuring the electrochemical oxidation of the 1-naphthol generated in the AP enzyme reaction upon 1-naphthyl phosphate (1-NPP) additions by differential pulse voltammetry (DPV). A calibration plot with a linear range between 5 and 100 pg mL 1 as well as a detection limit of 0.5 pg mL 1 (3sb/m) were achieved. This value is more than 27 times lower than that reported in the only voltammetric immunosensor for leptin described in the literature until now. The usefulness of the immunosensor was demonstrated by analyzing different types of real samples: human serum, infant powdered milk, and breast milk from a nursing mother with two months of breastfeeding.
Carbon nanotubes functionalized by click chemistry as scaffolds for the preparation of electrochemical immunosensors. Application to the determination of TGF-beta 1 cytokine
(RSC, 2016-10) Sánchez Tirado, Esther; González Cortés, Araceli; Yáñez Sedeño, Paloma; Pingarrón Carrazón, José Manuel
An electrochemical immunosensor for the determination of the multifunctional Transforming Growth Factor β1 (TGF-β1) cytokine has been prepared using multi-walled carbon nanotube (MWCNT)-modified screen-printed carbon electrodes. MWCNTs were functionalized by means of copper(i) catalyzed azide-alkyne cycloaddition ("click" chemistry) as an efficient strategy for the covalent immobilization of immunoreagents without altering their configurations and preserving their biological activity. Alkyne-functionalized IgGs were also prepared and used to assemble IgG-alkyne-azide-MWCNT conjugates used as scaffolds for the immunosensor preparation. After a blocking step with casein, anti-TGF was immobilized and the target cytokine was sandwiched with biotinylated anti-TGF labeled with poly-HRP-labeled streptavidin. The affinity reaction was monitored amperometrically at -0.20 V using the hydroquinone (HQ)/H2O2 system. The calibration plot for TGF-β1 exhibited a range of linearity (r2 = 0.995) extending between 5 and 200 pg mL-1 which is suitable for the determination of the target cytokine in human serum. A limit of detection of 1.3 pg mL-1 was achieved. The analytical performance of the immunosensor can be advantageously compared with that claimed for ELISA kits. The immunosensor was applied to the analysis of spiked human serum samples at different concentration levels with excellent recoveries.
Electrochemical immunosensor for the determination of 8-isoprostane aging biomarker using carbon nanohorns-modified disposable electrodes
(Elsevier, 2017-05) Sánchez Tirado, Esther; González Cortés, Araceli; Yudasaka, M.; Iijima, S.; Langa, Fernando; Yáñez Sedeño, Paloma; Pingarrón Carrazón, José Manuel
The first electrochemical immunosensor for the determination of 8-isoprostane (8-iso prostaglandin F2α, ISO), one of the most reliable biomarkers of lipid peroxidation in the human body and of aging related to Alzheimer´s disease or atherosclerosis is reported in this article. Disposable screen-printed carbon electrodes modified with carboxylated carbon nanohorns (CNHs) were employed as scaffolds for covalent immobilization of a specific anti-ISO antibody). A competitive immunoassay involving ISO and HRPlabeled antigen was designed and the determination of ISO was carried out by amperometry at -200 mV using the H2O2/hydroquinone (HQ) system. Under the optimized conditions, the immunosensor provides a linear response for ISO (r2 = 0.998) extending up to 700 pg/mL, which is suitable for the determination of the target compound in human serum. The analytical performance of the immunosensor improves that claimed for ELISA kits in terms of linearity of the calibration plot, precision, with RSD values lower than 1 % , and assay time (1h 30min), and exhibits a low limit of detection, 12 pg/mL, a long storage stability (30 days), and an excellent selectivity against other proteins that may be found in human serum. The analytical utility of the developed immunosensor was demonstrated by determining ISO in two types of human serum samples: lyophilized spiked serum, and real human serum from healthy male and female individuals with good results.
Electrochemical immunosensor for simultaneous determination of interleukin-1 beta and tumor necrosis factor alpha in serum and saliva using dual screen printed electrodes modified with functionalized double–walled carbon nanotubes
(Elsevier, 2016-12-23) Sánchez Tirado, Esther; Salvo, Coral; González Cortés, Araceli; Yáñez Sedeño, Paloma; Langa, Fernando; Pingarrón Carrazón, José Manuel
Dual screen-printed carbon electrodes modified with 4-carboxyphenyl-functionalized double-walled carbon nanotubes (HOOC-Phe-DWCNTs/SPCEs) have been used as scaffolds for the preparation of electrochemical immunosensors for the simultaneous determination of the cytokines Interleukin-1b (IL-1b) and factor necrosis tumor a (TNF-a). IL-1b. Capture antibodies were immobilized onto HOOC-Phe DWCNTs/SPCEs in an oriented form making using the commercial polymeric coating Mix&Go™. Sandwich type immunoassays with amperometric signal amplification through the use of poly-HRPstreptavidin conjugates and H2O2 as HRP substrate and hydroquinone as redox mediator were implemented. Upon optimization of the experimental variables affecting the immunosensor performance, the dual immunosensor allows ranges of linearity extending between 0.5 and 100 pg/mL and from 1 to 200 pg/mL for IL-1b and TNF-a, respectively, these ranges being adequate for the determination of the cytokines in clinical samples. The achieved limits of detection were 0.38 pg/mL (IL-1b) and 0.85 pg/mL (TNF-a). In addition, the dual immunosensor exhibits excellent reproducibility of the measurements, storage stability of the anti-IL-Phe-DWCNTs/SPCE and anti-TNF-Phe-DWCNTs/SPCE conjugates, and selectivity as well as negligible cross-talking. The dual immunosensor was applied to the simultaneous determination of IL-1b and TNF-a in human serum spiked at clinically relevant concentration levels and in real saliva samples.
Electrochemical magnetoimmunosensor for the ultrasensitive determination of interleukin-6 in saliva and urine using poly-HRP streptavidin conjugates as labels for signal amplification
(Springer, 2014) Ojeda, I; Moreno Guzmán, María; González Cortés, Araceli; Yáñez Sedeño, Paloma; Pingarrón Carrazón, José Manuel
A novel magnetoimmunosensor design for interleukin-6 (IL-6) which involved the covalent immobilization of anti-IL-6 antibodies onto carboxyl-functionalized magnetic microparticles and a sandwich-type immunoassay with signal amplification using poly-HRP-streptavidin conjugates is reported. All the variables concerning the preparation and the electroanalytical performance of the immunosensor were optimized. The use of poly-HRP-strept conjugates as enzymatic labels instead of conventional HRP-strept allowed enhanced signal-to-blank current ratios to be obtained. A linear calibration plot between the measured steady-state current and the log of IL-6 concentration was achieved in the 1.75 to 500 pg/mL range, which was not feasible when using HRP-strep as label. A limit of detection of 0.39 pg/mL IL-6 was obtained. The antiIL-6-MB conjugates exhibited an excellent storage stability providing amperometric responses with no significant loss during at least 36 days. The magnetoimmunosensor showed also an excellent selectivity against potentially interfering substances. The immunosensor was used to determine IL-6 in urine samples spiked at three different concentration levels with clinical relevance. Moreover, IL-6 was measured in three different saliva samples corresponding to a periodontitis patient, a smoker volunteer, and a non-smoker volunteer. The obtained results were statistically in agreement with those provided by a commercial ELISA kit.
I.amAble: la ciencia (química) al alcance de toda la sociedad
(2017-06-30) Herrero Domínguez, Santiago; Herrero Ansorregui, Irene; Martín Rodríguez, Pablo; Merí Bofí, Laura; Sobrino Gómez-Escalonilla, Inés; Valentín Pérez, Ángela; Azor Lafarga, Alberto; Calderón Saturio, Delia; Cilleros Prados, Olga; Hernández Díaz, Yolanda; Molero García, Julián; Sobrino Díaz, Lourdes; González Cortés, Araceli; Mena Fernández, María Luz; Muñoz Olivas, Riansares; Martínez del Pozo, Álvaro; González Prieto, Rodrigo; Jiménez Aparicio, Reyes; Priego Bermejo, José Luis; Varela Losada, Áurea; Mancheño Real, María José; Osío Barcina, José; Guerrero Martínez, Andrés; Cabañas Poveda, Albertina; Bautista Blasco, Susana; Gervás Gómez-Navarro, Pablo; González Acebrón, Laura; Méndez Pozo, Gonzalo; Pavón Mestras, Juan; Desvoyes, Bénédicte; Landa Cánovas, Ángel; Fernández Rodríguez, Juan Miguel; Perles Hernáez, Josefina
En este proyecto de innovación, que nace con vocación de continuar en años sucesivos, se persigue mejorar la calidad de la formación de los estudiantes de la Facultad de Ciencias Químicas (F. CC.QQ.) en el ámbito de la docencia teórico-práctica y de la divulgación científica. El trabajo ha consistido en la preparación de unos experimentos prácticos para llevarlos a cabo en centros educativos no universitarios en los que se ha tenido en cuenta la participación conjunta de personas con y sin diversidad funcional, desde una perspectiva inclusiva colaborativa. Estas actividades las han realizado los estudiantes bajo la supervisión de profesores (PDI) y personal de administración y servicios (PAS). Los experimentos se han recogido en fichas didácticas para facilitar su desarrollo y aplicación por parte de otros usuarios. En estas fichas se explica detalladamente cómo realizar las experiencias en formato de taller. Las fichas de los talleres realizados están disponibles en una página web vinculada a la Universidad Complutense bajo el título I.amAble (iamable.ucm.es). Está página ha sido construida por un estudiante de la Facultad de Informática , bajo la supervisión de profesionales, tanto de esa facultad como del Instituto de Tecnología del Conocimiento, y está abierta a contribuciones similares de otras facultades y otras instituciones. La página web está diseñada de manera que resulte lo más intuitiva y accesible posible para todo tipo de público. Entre todos los experimentos se han elegido cuatro para llevarlos a la práctica en centros educativos como actividades inclusivas en las que han participado conjuntamente personas con y sin discapacidad. Con este proyecto se pretende mejorar la calidad docente al ofrecer a los estudiantes la posibilidad de aprender enseñando mediante una actividad semipresencial. El desarrollo por parte de los estudiantes de competencias transversales en educación y en divulgación de la ciencia facilitarán algunas salidas profesionales en el ámbito educativo formal (centros de enseñanza) o informal (museos, animación sociocultural). Otro aspecto importante a resaltar es la potenciación de la colaboración entre todos los miembros de la institución universitaria. Este proyecto pretende contribuir a la mejora de la cultura científica, así como al establecimiento de puentes entre la UCM y la sociedad a la que debe servir. Finalmente, es importante subrayar que incidirá en la inclusión de las personas con discapacidad como parte de la sociedad, a través del acercamiento compartido a la ciencia (Dimensiones de inclusión social y derechos de Schalock; NAVAS MACHO, P. y otros, 2012. Derechos de las personas con discapacidad intelectual: implicaciones de la Convención de Naciones Unidas. Siglo Cero. 43 (243): 7-28.).
Implementación de la metodología flipped classroom en los laboratorios de Química Analítica
(2023-05-31) Reviejo García, Ángel Julio; Agüí Chicharro, María Lourdes; Campuzano Ruiz, Susana; Gamella Carballo, Maria; García Martín, Ángel Felipe; González Cortés, Araceli; Guerrero Blanco, José Ignacio; Mateos Briz, María Raquel; Miguel Bravo, María; Pérez Ginés, Víctor; Reviejo Martínez, Eva; Romano Martín, Santiago; Ruiz-Valdepeñas Montiel, Víctor; Sánchez Tirado, Esther; Santiago Sáez, Andrés Sebastián; Serafín González-Carrato, Verónica; Torrente Rodríguez, Rebeca Magnolia; Yáñez-Sedeño, Paloma; Pedrero Muñoz, María
Adaptar el sistema tradicional de aprendizaje a las necesidades actuales del alumnado empleando la metodología flipped classroom en el laboratorio de Química Analítica I, con el objetivo de fomentar el aprendizaje utilizando herramientas digitales.
Copper(I)-Catalyzed Click Chemistry as a Tool for the Functionalization of Nanomaterials and the Preparation of Electrochemical (Bio)Sensors
(MDPI, 2019-05-24) Yáñez Sedeño, Paloma; González Cortés, Araceli; Campuzano Ruiz, Susana; Pingarrón Carrazón, José Manuel
Proper functionalization of electrode surfaces and/or nanomaterials plays a crucial role in the preparation of electrochemical (bio)sensors and their resulting performance. In this context, copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) has been demonstrated to be a powerful strategy due to the high yields achieved, absence of by-products and moderate conditions required both in aqueous medium and under physiological conditions. This particular chemistry offers great potential to functionalize a wide variety of electrode surfaces, nanomaterials, metallophthalocyanines (MPcs) and polymers, thus providing electrochemical platforms with improved electrocatalytic ability and allowing the stable, reproducible and functional integration of a wide range of nanomaterials and/or different biomolecules (enzymes, antibodies, nucleic acids and peptides). Considering the rapid progress in the field, and the potential of this technology, this review paper outlines the unique features imparted by this particular reaction in the development of electrochemical sensors through the discussion of representative examples of the methods mainly reported over the last five years. Special attention has been paid to electrochemical (bio)sensors prepared using nanomaterials and applied to the determination of relevant analytes at different molecular levels. Current challenges and future directions in this field are also briefly pointed out.
Multiplexed Ultrasensitive Determination of Adrenocorticotropin and Cortisol Hormones at a Dual Electrochemical Immunosensor
(Wiley-VCH, 2012-05) Moreno Guzmán, María; González Cortés, Araceli; Yañez Sedeño, Paloma
A novel dual electrochemical immunosensor for the multiplexed determination of adrenocorticotropin (ACTH) and cortisol is reported. Aminophenylboronic acid-modified dual screen-printed carbon electrodes were prepared on which the corresponding ACTH and cortisol antibodies were immobilized. Competitive immunoassays involved biotinylated ACTH and alkaline phosphatase labelled streptavidin, or alkaline phosphatase labelled cortisol. Differential pulse voltammetry upon 1-naphtyl phosphate addition was employed to monitor the affinity reactions. The ranges of linearity were 5.0×10−5−0.1 and 0.1−500 ng/mL for ACTH and cortisol. The usefulness of the dual immunosensor was demonstrated by analyzing certified human serum samples with good recoveries.