Person: Moreno Guzmán, María
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First Name
María
Last Name
Moreno Guzmán
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Farmacia
Department
Química en Ciencias Farmacéuticas
Area
Química Analítica
Identifiers
8 results
Search Results
Now showing 1 - 8 of 8
Item Ultrasensitive detection of adrenocorticotropin hormone (ACTH) using disposable phenylboronic-modified electrochemical immunosensors(Biosensors and Bioelectronics, 2012) Moreno Guzmán, María; Ojeda, Irene; Villalonga, Reynaldo; González Cortés, Araceli; Yáñez Sedeño, Paloma; Pingarrón Carrazón, José ManuelThis work reports for the first time an electrochemical immunosensor for the determination of adrenocorticotropin hormone (ACTH). The immunoelectrode design involves the use of amino phenylboronic acid for the oriented immobilization of anti-ACTH antibodies onto screen-printed carbon modified electrode surfaces. A competitive immunoassay between the antigen and the biotinylated hormone for the binding sites of the immobilized antibody was performed. The electroanalytical response was generated by using alkaline phosphatase-labelled streptavidin and 1-naphtyl phosphate as the enzyme substrate. The electrochemical oxidation of the enzyme reaction product, 1-naphtol, measured by differential pulse voltammetry was employed to monitor the affinity reaction. Under the optimized working conditions, an extremely low detection limit of 18 pg/L was obtained. Cross-reactivity was evaluated against other hormones (cortisol, estradiol, testosterone, progesterone, hGH and prolactin) and the obtained results demonstrated an excellent selectivity. The developed immunosensor was applied to a human serum sample containing a certified amount of ACTH with good results.Item Multiplexed Ultrasensitive Determination of Adrenocorticotropin and Cortisol Hormones at a Dual Electrochemical Immunosensor(Electroanalysis, 2012) Moreno Guzmán, María; González Cortés, Araceli; Yañez Sedeño, PalomaA 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.Item Electrochemical magnetoimmunosensor for the ultrasensitive determination of interleukin-6 in saliva and urine using poly-HRP streptavidin conjugates as labels for signal amplification(Analytical and Bioanalytical Chemistry, 2014) Ojeda, I; Moreno Guzmán, María; González Cortés, Araceli; Yáñez Sedeño, Paloma; Pingarrón Carrazón, José ManuelA 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.Item A disposable electrochemical immunosensor for the determination of leptin in serum and breast milk(Analyst, 2013) Ojeda, Irene; Moreno Guzmán, María; González Cortés, Araceli; Yáñez Sedeño, Paloma; Pingarrón Carrazón, José ManuelThe 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.Item Electrochemical Magnetic Immunosensors for the Determination of Ceruloplasmin(Electroanalysis, 2013) Ojeda Fernández, Irene; Moreno Guzmán, María; González Cortés, Araceli; Yáñez Sedeño, Paloma; Pingarrón Carrazón, José ManuelElectrochemical immunosensors for ceruloplasmin (Cp) are reported for the first time. Two configurations involving magnetic beads (MBs) functionalized with Protein A or Streptavidin for immobilization of Cp antibodies were compared, using competitive immunoassay with synthesized alkaline phosphatase-Cp conjugate. Upon capturing MBs-immunoconjugates onto screen-printed carbon electrodes, quantification of Cp was accomplished by DPV measurement of 1-naphthol generated after 1-naphthylphosphate addition. Linear ranges of calibration curves and detection limits were 0.1–1000 µg/mL and 0.040 µg/mL (Protein A-MBs), and 0.025–20 µg/mL and 0.018 µg/mL (Strept-MBs). Good results were obtained in the determination of Cp in spiked human serum samples.Item Amperometric immunosensor for the determination of ceruloplasmin in human serum and urine based on covalent binding to carbon nanotubes-modified screen-printed electrodes(Talanta, 2013) Garcinuño, Belit; Ojeda Fernández, Irene; Moreno Guzmán, María; González Cortés, Araceli; Yáñez-Sedeño Orive, Paloma; Pingarrón Carrazón, José ManuelA novel electrochemical immunosensor for the determination of ceruloplasmin (Cp) in human serum and urine is reported. The immunosensor configuration involves an indirect competitive immunoassay implying covalent immobilization of Cp on activated carboxylic groups at carbon nanotubes-modified screen-printed electrodes (CNTs/SPE). After Cp immobilization and reaction between the target analyte and anti-ceruloplasmin antibodies in solution, the remaining non-conjugated antibody is attached on the Cp-CNTs modified electrode. Monitoring of Cp is performed by means of a secondary antibody labeled with peroxidase (HRP-anti-IgG) and measurement of the amperometric current resulting from the addition of hydrogen peroxide in the presence of hydroquinone as the redox mediator. The experimental variables affecting the analytical performance of the immunosensor were optimized. Calibration curves for Cp provided a linear range between 0.07 and 250 μg/mL (r=0.997). The limit of detection achieved was 21 ng/mL. These analytical characteristics allow the immunosensor to be successfully used for the determination of Cp in spiked human serum and urine at various concentration levelsItem Carbon Nanohorns as a Scaffold for the Construction of Disposable Electrochemical Immunosensing Platforms. Application to the Determination of Fibrinogen in Human Plasma and Urine(Analytical Chemistry, 2014) Ojeda Fernández, Irene; Garcinuño, Belit; Moreno Guzmán, María; González Cortés, Araceli; Yudasaka, Masako; Iijima, Sumio; Langa, Fernando; Yáñez-Sedeño Orive, Paloma; Pingarrón Carrazón, José ManuelWe describe in this work a novel electrochemical immunosensor design making use of carbon nanohorns (CNHs) as a scaffold for the preparation of disposable immunosensing platforms for the determination of fibrinogen (Fib). The approach involved the immobilization of Fib onto activated CNHs deposited on screen-printed carbon electrodes (SPCEs) and the implementation of an indirect competitive assay using anti-Fib labeled with horseradish peroxidase (HRP) and hydroquinone (HQ) as the redox mediator. Both CNHs and the Fib-CNHs covalent assembly were characterized by microscopic and electrochemical techniques. The different variables affecting the analytical performance of the amperometric immunosensing strategy were optimized. The calibration plot for Fib allowed a range of linearity between 0.1 and 100 μg/mL (r 2 = 0.994) and a detection limit of 58 ng/ mL to be achieved. The Fib-CNHs/SPCEs exhibited an excellent storage stability of at least 42 days. The developed immunosensor provides, in general, an analytical performance better than that reported for other Fib immunosensors and commercial ELISA kits. This simple and relatively low cost immunosensor configuration permitted the sensitive and selective determination of Fib in human plasma and urineItem Electrochemical immunosensor for rapid and sensitive determination of estradiol(Analytica Chimica Acta, 2012) Ojeda Fernández, Irene; Lopez-Montero, Judith; Moreno Guzmán, María; Janegitz, Bruno; González Cortés, Araceli; Yáñez-Sedeño Orive, Paloma; Pingarrón Carrazón, José ManuelThis work describes the preparation of an electrochemical immunosensor for estradiol based on the surface modification of a screen printed carbon electrode with grafted p-aminobenzoic acid followed by covalent binding of streptavidin (Strept) and immobilization of biotinylated anti-estradiol (antiestradiol-Biotin). The hormone determination was performed by applying a competitive immunoassay with peroxidase-labelled estradiol (HRP–estradiol) and measurement of the amperometric response at −200 mV using hydroquinone (HQ) as redox mediator. The calibration curve for estradiol exhibited a linear range between 1 and 250 pg mL−1 (r = 0.990) and a detection limit of 0.77 pg mL−1 was achieved. Cross-reactivity studies with other hormones related with estradiol at physiological concentration levels revealed the practical specificity of the developed method for estradiol. A good reproducibility, with RSD = 5.9% (n = 8) was also observed. The operating stability of a single bioelectrode modified with anti-estradiol-Biotin-Strept was nine days when it was stored at 8 ◦C under humid conditions between measurements. The developed immunosensor was applied to the analysis of certified serum and spiked urine samples with good results