Person: Canales Mayordomo, María Ángeles
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First Name
María Ángeles
Last Name
Canales Mayordomo
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Orgánica
Area
Química Orgánica
Identifiers
2 results
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Item Competitive upconversion-linked immunoassay using peptide mimetics for the detection of the mycotoxin zearalenone(Biosensors and Bioelectronics, 2020) Peltomaa, Riikka Johanna; Farka, Zdeněk; Mickert, Matthias ; Brandmeier, Julian ; Pastucha, Matěj; Hlaváček, Antonín; Martínez Orts, Mónica; Canales Mayordomo, María Ángeles; Skládal, Petr; Benito Peña, María Elena; Moreno Bondi, María Cruz; Gorris, HansDue to increasing food safety standards, the analysis of mycotoxins has become essential in the food industry. In this work, we have developed a competitive upconversion-linked immunosorbent assay (ULISA) for the analysis of zearalenone (ZEA), one of the most frequently encountered mycotoxins in food worldwide. Instead of a toxin-conjugate conventionally used in competitive immunoassays, we designed a ZEA mimicking peptide extended by a biotin-linker and confirmed its excellent suitability to mimic ZEA by nuclear magnetic resonance (NMR) and surface plasmon resonance (SPR) analysis. Upconversion nanoparticles (UCNP, type NaYF4:Yb,Tm) served as background-free optical label for the detection of the peptide mimetic in the competitive ULISA. Streptavidin-conjugated UCNPs were prepared by click reaction using an alkyne-PEG-neridronate linker. The UCNP conjugate clearly outperformed conventional labels such as enzymes or fluorescent dyes. With a limit of detection of 20 pg mL−1 (63 pM), the competitive ULISA is well applicable to the detection of ZEA at the levels set by the European legislation. Moreover, the ULISA is specific for ZEA and its metabolites (α- and β-zearalenol) without significant cross-reactivity with other related mycotoxins. We detected ZEA in spiked and naturally contaminated maize samples using liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) as a reference method to demonstrate food analysis in real samples.Item Homogeneous immunoassay for cyclopiazonic acid based upon mimotopes and upconversion-resonance energy transfer(Biosensors and Bioelectronics, 2023) Prádanas González, Fernando; Peltomaa, Riikka Johanna; Lahtinen, Satu; Luque Uria, Álvaro; Más, Vicente ; Barderas, Rodrigo ; Maragos, Chris ; Canales Mayordomo, María Ángeles; Soukka, Terro; Benito Peña, María Elena; Moreno Bondi, María CruzStrains of Penicillium spp. are used for fungi-ripened cheeses and Aspergillus spp. routinely contaminate maize and other crops. Some of these strains can produce toxic secondary metabolites (mycotoxins), including the neurotoxin α-cyclopiazonic acid (CPA). In this work, we developed a homogeneous upconversion-resonance energy transfer (UC-RET) immunoassay for the detection of CPA using a novel epitope mimicking peptide, or mimotope, selected by phage display. CPA-specific antibody was used to isolate mimotopes from a cyclic 7-mer peptide library in consecutive selection rounds. Enrichment of antibody binding phages was achieved, and the analysis of individual phage clones revealed four different mimotope peptide sequences. The mimotope sequence, ACNWWDLTLC, performed best in phage-based immunoassays, surface plasmon resonance binding analyses, and UC-RET-based immunoassays. To develop a homogeneous assay, upconversion nanoparticles (UCNP, type NaYF4:Yb3+, Er3+) were used as energy donors and coated with streptavidin to anchor the synthetic biotinylated mimotope. Alexa Fluor 555, used as an energy acceptor, was conjugated to the anti-CPA antibody fragment. The homogeneous single-step immunoassay could detect CPA in just 5 min and enabled a limit of detection (LOD) of 30 pg/mL (1.5 μg/kg) and an IC50 value of 0.36 ng/mL. No significant cross-reactivity was observed with other co-produced mycotoxins. Finally, we applied the novel method for the detection of CPA in spiked maize samples using high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD) as a reference method.