2026-07-03T09:34:07Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/933162024-08-06T00:00:57Zcom_20.500.14352_14col_20.500.14352_15

Homogeneous quenching immunoassay for fumonisin B1 based on gold nanoparticles and an epitope-mimicking yellow fluorescent protein Peltomaa, Riikka Johanna Amaro Torres, Francisco Carrasco, Sergio Orellana Moraleda, Guillermo Benito Peña, María Elena Moreno Bondi, María Cruz Homogeneous immunoassays represent an attractive alternative to traditional heterogeneous assays due to their simplicity, sensitivity, and speed. On the basis of a previously identified epitope-mimicking peptide, or mimotope, we developed a homogeneous fluorescence quenching immunoassay based on gold nanoparticles (AuNPs) and a recombinant epitope-mimicking fusion protein for the detection of mycotoxin fumonisin B1 (FB1). The fumonisin mimotope was cloned as a fusion protein with a yellow fluorescent protein that could be used directly as the tracer for FB1 detection without the need of labeling or a secondary antibody. Furthermore, owing to the fluorescence quenching ability of AuNPs, a homogeneous immunoassay could be performed in a single step without washing steps to separate the unbound tracer. The homogeneous quenching assay showed negligible matrix effects in 5% wheat extract and high sensitivity for FB1 detection, with a dynamic range from 7.3 to 22.6 ng/mL, a detection limit of 1.1 ng/mL, and IC50 value of 12.9 ng/mL, which was significantly lower than the IC50 value of the previously reported assay using the synthetic counterpart of the same mimotope in a microarray format. The homogeneous assay was demonstrated to be specific for fumonisins B1 and B2, as no significant cross-reactivity with other mycotoxins was observed, and acceptable recoveries (86% for FB1 2000 μg/kg and 103% for FB1 4000 μg/kg), with relative standard deviation less than 6.5%, were reported from spiked wheat samples, proving that the method could provide a valuable tool for simple analysis of mycotoxin-contaminated food samples. 2024-01-16T10:51:44Z 2024-01-16T10:51:44Z 2024-01-16T10:51:44Z 2018 journal article https://hdl.handle.net/20.500.14352/93316 1936-0851 10.1021/acsnano.8b06094 1936-086X eng CTQ2015-69278-C2 (MINECO, CTQ201569278C2) Riikka Peltomaa, Francisco Amaro-Torres, Sergio Carrasco, Guillermo Orellana, Elena Benito-Peña, and María C. Moreno-Bondi ACS Nano 2018 12 (11), 11333-11342 DOI: 10.1021/acsnano.8b06094 http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 International American Chemical Society