Suchergebnisse

The relevance of the linker tethering site in haptens was investigated for antibody generation and immunoassay development. Three derivatives of the strobilurin fungicide picoxystrobin were synthesized with the same functionalized spacer arm located at three different positions. Protein conjugates of those haptens were employed as immunogens, and novel polyclonal antibodies were produced and characterized. All haptens afforded highly specific antibodies, but different affinities to the free analyte were observed among the obtained antisera. Next, competitive enzyme-linked immunosorbent assays were studied in several formats, and site heterology was confirmed as an effective strategy for detectability improvement. An indirect heterologous immunoassay was eventually selected and optimized, showing a limit of detection for picoxystrobin of 0.02 μg/L and a working range between 0.03 and 1.30 μg/L. Finally, the developed extraction and analytical procedures revealed a practical limit of quantification of 5 μg/kg for this fungicide in soybean sprouts, well below the maximum residue limits in the European Union. © 2011 Elsevier Inc. All rights reserved. ; This work was supported by Ministerio de Educación y Ciencia (AGL2006-12750-C02-01/02/ALI) and cofinanced by FEDER funds. J.P. was hired by Consejo Superior de Investigaciones Científicas (CSIC) under a predoctoral I3P contract of Ministerio de Ciencia e Innovación and the European Social Fund. F.A.E.-T. and J.V.M. were hired by CSIC with postdoctoral contracts, the former under the Juan de la Cierva Program and the latter under the Ramón y Cajal Program, both cofinanced by Ministerio de Ciencia e Innovación and the European Social Fund. ; Peer Reviewed

Cyprodinil is among the most common agrochemical residues found in highly perishable fruits, such as strawberries. In the present study, high-affinity monoclonal antibodies to this anilinopyrimidine fungicide were raised for the first time with the aim to produce valuable immunochemical analytical assays. Cyprodinil bioconjugates and the generated novel monoclonal antibodies were employed for sensitive competitive immunoassay development in two different formats. The limits of detection of the optimized assays were 20 and 30 ng L -1 for the indirect and direct assay, respectively. Influence over assay parameters of different physicochemical factors was studied. Strawberry samples were extracted following the recommended QuEChERS procedure for pesticide residues in food, and analyzed by the optimized immunoassays. Recoveries and coefficients of variation from fortified samples were within standard values. In addition, the obtained immunochemical results with naturally contaminated samples were statistically comparable, according to Deming regression analysis, to those of a reference chromatographic method. ; This work was supported by the Spanish Ministerio de Ciencia e Innovación (AGL2009-12940-C02-01-02/ALI and AGL2012-39965-C02-01-02/ALI) and cofinanced by FEDER Funds. J.V.M. and F.A.E.-T. were hired by the Consejo Superior de Investigaciones Científicas (CSIC), the former under a Ramón y Cajal contract and the latter under a JAE-doc contract, both of them financed by Ministerio de Ciencia e Innovación and the European Social Fund – European Union. G.Q.-R. is a recipient of a PROMEP predoctoral fellowship from Secretaría de Educación Pública of the Mexican government. Proteomic analysis was carried out in the SCIE University of Valencia Proteomics Unit, a member of the ISCIII ProteoRedProteomics Platform. ; Peer Reviewed