Person: Povedano Muñumel, Eloy
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First Name
Eloy
Last Name
Povedano Muñumel
Affiliation
Universidad Complutense de Madrid
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Item Disposable Amperometric Immunosensor for the Detection of Adulteration in Milk through Single or Multiplexed Determination of Bovine, Ovine, or Caprine Immunoglobulins G(Analytical Chemistry, 2019) Ruiz Valdepeñas Montiel, Víctor; Povedano Muñumel, Eloy; Benedé Pérez, Sara; Mata, Luis; Galán-Malo, Patricia; Gamella, María; Reviejo García, Ángel Julio; Campuzano Ruiz, Susana; Pingarrón Carrazón, José ManuelThis paper reports the first immunoplatforms for the detection of adulteration in milk with milk or colostrum from other animals. The developed electrochemical bioplatforms allow the reliable determination of immunoglobulins G (IgGs) from cows, sheeps, or goats. They rely on sandwiching each animal species-specific IgGs with selective antibody pairs [unconjugated and conjugated with horseradish peroxidase (HRP)] onto magnetic microbeads (MBs) used as solid supports and amperometric transduction with the hydrogen peroxide/hydroquinone (HQ) system at disposable electrodes. The immunoplatforms allow achieving limits of detection (LODs) of 0.74, 0.82, and 0.66 ng/mL for bovine, ovine, and caprine IgGs, respectively, which are lower than those obtained with conventional enzyme-linked immunosorbent assay (ELISA) methodologies and in 2–5 times shorter time. The bioplatforms were successfully applied to the determination of the individual content of the target IgGs in milk samples of different animals (cow, sheep, and goat) and type (colostrum, raw, and pasteurized), without matrix effect and after just a sample dilution. They were also applied to the detection of adulteration with milks from other animals at levels below than those required by the European legislation (1.0%, v/v). The possibility to detect milk adulteration with colostrum using a strategy based on the measurement of the total content of the three target IgGs in raw milks is also demonstrated. Multiplexing platforms were constructed to be used in routine surveillance of milk. They are able to provide in a single run and in just 30 min relevant information regarding the milk sample including its animal origin, the undergone heat treatment, and whether it was adulterated with milk or colostrum from other species.Item Comparison of Different Strategies for the Development of Highly Sensitive Electrochemical Nucleic Acid Biosensors Using Neither Nanomaterials nor Nucleic Acid Amplification(ACS Sensors, 2017) Ruiz Valdepeñas Montiel, Víctor; Povedano Muñumel, Eloy; Vargas, Eva; Torrente Rodríguez, Rebeca Magnolia; Pedrero Muñoz, María; Reviejo García, Ángel Julio; Campuzano Ruiz, Susana; Pingarrón Carrazón, José ManuelCurrently, electrochemical nucleic acid-based biosensing methodologies involving hybridization assays, specific recognition of RNA/DNA and RNA/RNAduplexes, and amplification systems provide an attractive alternative to conventional quantification strategies for the routine determination of relevant nucleic acids at different settings. A particularly relevant objective in the development of such nucleic acid biosensors is the design of as many as possible affordable, quick, and simple methods while keeping the required sensitivity. With this aim in mind, this work reports, for the first time, a thorough comparison between 11 methodologies that involve different assay formats and labeling strategies for targeting the same DNA. The assayed approaches use conventional sandwich and competitive hybridization assays, direct hybridization coupled to bioreceptors with affinity for RNA/DNA duplexes, multienzyme labeling bioreagents, and DNA concatamers. All of them have been implemented on the surface of magnetic beads (MBs) and involve amperometrictransduction at screen-printed carbon electrodes (SPCEs). The influence of the formed duplex length and of the labeling strategy have also been evaluated. Results demonstrate that these strategies can provide very sensitive methods without the need for using nanomaterials or polymerase chain reaction (PCR). In addition, the sensitivity can be tailored within several orders of magnitude simply by varying the bioassay format, hybrid length or labeling strategy. This comparative study allowed us to conclude that the use of strategies involving longer hybrids, the use of antibodies with specificity for RNA/DNA heteroduplexes and labeling with bacterial antibody binding proteins conjugated with multiple enzyme molecules, provides the best sensitivity.Item Magnetic microbeads-based amperometric immunoplatform for the rapid and sensitive detection of N6-methyladenosine to assist in metastatic cancer cells discrimination(Biosensors and Bioelectronics, 2021) Povedano Muñumel, Eloy; Gamella Carballo, María; Torrente Rodríguez, Rebeca Magnolia; Montero-Calle, Ana; Pedrero Muñoz, María; Solís-Fernández, Guillermo; Navarro Villoslada, Fernando; Barderas, Rodrigo; Campuzano Ruiz, Susana; Pingarrón Carrazón, José ManuelThis work describes the preparation of an immunoplatform for the sensitive and selective determination of N6-methyladenosine (m6A). The simple and fast protocol involves for the first time the use of micromagnetic immunoconjugates to establish a direct competitive assay between the m6A target and a biotinylated RNA oligomer bearing a single m6A enzymatically labelled with a commercial conjugate of streptavidin-peroxidase (Strep-HRP) as tracer. The cathodic current change measured in the presence of H2O2/hydroquinone (HQ) at screen-printed carbon electrodes (SPCEs) upon surface capturing the magnetic bioconjugates is inversely proportional to the m6A target concentration. After evaluating the effect of key variables, the analytical characteristics were established for the determination of three different targets: the N6-methyladenosine-5′ -triphosphate (m6ATP) ribonucleotide, a short synthetic RNA oligomer bearing a single m6A and the positive control provided in a commercial colorimetric kit for m6A-RNA quantification. The obtained results show that this immunoplatform is competitive with other methods reported to date, achieving an improved sensitivity (limit of detection of 0.9 pM for the short synthetic oligomer) using a much simpler and faster protocol (~1 h) and disposable electrodes for the transduction. Furthermore, the applicability for discriminating the metastatic potential of cancer cells by directly analyzing a small amount of raw total RNA without enriching or fragmenting was also preliminary assessed.