Peltomaa, Riikka JohannaFarka, ZdeněkMickert, MatthiasBrandmeier, JulianPastucha, MatějHlaváček, AntonínMartínez Orts, MónicaCanales Mayordomo, María ÁngelesSkládal, PetrBenito Peña, María ElenaMoreno Bondi, María CruzGorris, Hans2024-02-122024-02-122020Peltomaa, Riikka, et al. «Competitive Upconversion-Linked Immunoassay Using Peptide Mimetics for the Detection of the Mycotoxin Zearalenone». Biosensors and Bioelectronics, vol. 170, diciembre de 2020, p. 112683. https://doi.org/10.1016/j.bios.2020.112683.10.1016/j.bios.2020.112683https://hdl.handle.net/20.500.14352/101131Due 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.engAttribution-NonCommercial-NoDerivatives 4.0 Internationaljournal articlehttps://www.doi.org/10.1016/j.bios.2020.112683open access546ZearalenoneUpconversion nanoparticlePeptide mimeticImmunosensingSurface plasmon resonanceFood safetyCienciasCiencias Biomédicas23 Química24 Ciencias de la Vida