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Alternariol is an emerging mycotoxin that may be present in many foods at relatively high concentrations. Therefore, sensitive analytical methods are needed to reduce human exposure to this secondary fungal metabolite. The aim of the present study was to develop alternative immunochemical methods for the rapid analysis of alternariol using novel homemade monoclonal antibodies. In this study, a direct competitive enzyme-linked immunosorbent assay for alternariol is reported for the first time, with an IC50 value and a detection limit of 0.020 ng/mL and 0.004 ng/mL, respectively. Under the optimized immunoassay conditions, alternariol could be accurately and precisely quantified in fruit juice samples in only 25 min. In addition, a nanoparticle-based lateral-flow immunochromatography assay with an IC50 value and a visual detection limit of 0.24 ng/mL and 1 ng/mL, respectively, was developed. This immunoassay was validated according to European guidelines for portable semiquantitative analytical methods. Thus, juice samples with alternariol levels above 4 ng/mL were detected by this rapid method in only 15 min, with a negligible false suspect rate.

Alternariol is a toxic secondary metabolite produced by Alternaria fungi. Nowadays, this mycotoxin can be found in many products of plant origin at concerning concentrations. The aim of the present study was to develop a highly sensitive and selective immunochemical method for the analysis of alternariol. To this end, hapten synthesis was carried out from the scratch and specific high-affinity monoclonal antibodies to alternariol were generated by using, for the first time, alternariol bioconjugates with unambiguous linker tethering sites. A novel indirect enzyme-linked immunosorbent assay that incorporated a rationally designed heterologous conjugate was developed. The optimized assay showed an outstanding half-maximal inhibition concentration for alternariol below 0.04 ng/mL, and no cross-reactivity with alternariol monomethyl ether was observed. Very good recovery values and coefficients of variation were obtained from the analysis of alternariol-fortified fruit and cereal flour samples. Finally, alternariol was quantitatively determined in pears that had been previously infected with Alternaria alternata, showing excellent correlation with liquid chromatography results.

Highly active antiretroviral therapy (HAART) includes very potent drugs that are often characterized by high toxicity. Tenofovir (TFV) is a widely used drug prescribed mainly for pre-exposure prophylaxis (PreP) and the treatment of human immunodeficiency virus (HIV). The therapeutic range of TFV is narrow, and adverse effects occur with both underdose and overdose. The main factor contributing to therapeutic failure is the improper management of TFV, which may be caused by low compliance or patient variability. An important tool to prevent inappropriate administration is therapeutic drug monitoring (TDM) of compliance-relevant concentrations (ARCs) of TFV. TDM is performed routinely using time-consuming and expensive chromatographic methods coupled with mass spectrometry. Immunoassays, such as enzyme-linked immunosorbent assays (ELISAs) and lateral flow immunoassays (LFIAs), are based on antibody–antigen specific recognition and represent key tools for real-time quantitative and qualitative screening for point-of-care testing (POCT). Since saliva is a non-invasive and non-infectious biological sample, it is well-suited for TDM. However, saliva is expected to have a very low ARC for TFV, so tests with high sensitivity are required. Here, we have developed and validated a highly sensitive ELISA (IC50 1.2 ng/mL, dynamic range 0.4–10 ng/mL) that allows the quantification of TFV in saliva at ARCs and an extremely sensitive LFIA (visual LOD 0.5 ng/mL) that is able to distinguish between optimal and suboptimal ARCs of TFV in untreated saliva.

The present invention relates to bioconjugates and labeled derivatives of the adducts formed by the reaction of patulin with benzene-1,2-dithiols or their salts. Said conjugates are suitable for the production of antibodies capable of recognizing the aforementioned patulin-(benzene-1,2-dithiols) adducts with high affinity and specificity. Likewise, the present invention also relates to the use of bioconjugates of patulin-(benzene-1,2-dithiols) adducts and of labeled derivatives thereof as assay antigens. Furthermore, the present invention also relates to immunochemical methods for the analysis of patulin, using the bioconjugates and labeled derivatives and antibodies of the invention, which include a previous step to quantitatively convert patulin into these adducts. This invention also provides a kit for analyzing patulin comprising a benzene-1,2-dithiol or its salts, antibodies against patulin-(benzene-1,2-dithiols) adducts, and assay antigens.

Weed resistance to glyphosate has been a driving force behind the increased use of alternative herbicides in agriculture. Recently, dicamba-tolerant recombinant plants were introduced to the market, which may result in residues of this agrochemical contaminating environmental waters. Given that restrictions on the use of dicamba have consequently been established by regulatory agencies, it is therefore also desirable to conduct extensive controls on dicamba residues. Immunoassays are currently the most powerful bioanalytical technology for the rapid monitoring of chemical residues and contaminants. In the present study, a novel hapten was designed maintaining unaltered all the antigenic moieties of the target molecule, and this was used to generate high-affinity monoclonal antibodies against dicamba for the first time. Additionally, a collection of haptens with different linker composition or linker tethering site was synthesized and conjugated to proteins. Using these novel immunoreagents, a direct competitive enzyme-linked immunosorbent assay with a limit of detection for dicamba of 0.24 ng/mL was developed and validated. Analysis of water samples from different origins afforded recovery values between 90 % and 120 %, and coefficients of variation below 20 % were obtained. These results indicate that the developed immunochemical assay is suitable for the rapid determination of dicamba residues in environmental water samples.

Algal blooms that contaminate freshwater resources with cyanotoxins constitute, nowadays, a global concern. To deal with this problem, a variety of analytical methods, including immunochemical assays, are available for the main algal toxins, for example, microcystins, nodularins, and saxitoxins, with the remarkable exception of anatoxin-a. Now, for the first time, highly sensitive, enantioselective immunoassays for anatoxin-a have been validated using homemade monoclonal antibodies. Two competitive enzyme-linked immunosorbent assays were developed in different formats, with detection limits for (+)-anatoxin-a of 0.1 ng/mL. Excellent recovery values between 82 and 117%, and coefficients of variation below 20%, were observed using environmental water samples fortified between 0.5 and 500 ng/mL. In addition, a lateral-flow immunochromatographic assay was optimized for visual and instrumental reading of results. This test showed a visual detection limit for (+)-anatoxin-a of 4 ng/mL. Performance with a reader was validated in accordance with the European guidelines for semiquantitative rapid methods for small chemical contaminants. Thus, at a screening target concentration of 2 ng/mL, the probability of a blank sample to be classified as "suspect" was as low as 0.2%. Finally, the optimized direct enzyme immunoassay was validated by comparison with high-performance liquid chromatography-tandem mass spectroscopy data and showed a good correlation (r = 0.995) with a slope of 0.94. Moreover, environmental water samples containing more than 2 ng/mL of anatoxin-a were detected by the developed dipstick assay. These results provide supplementary and complementary strategies for monitoring the presence of anatoxin-a in water.

Appropriate hapten design and synthesis have been identified as critical steps to gener-ate high-performance immunoreagents and to develop sensitive and selective immunoanalytical methods. Antibodies and immunoassays for the major mycotoxin zearalenone have been reported and marketed. However, zearalenone haptens have mostly been prepared by the oxime active ester technique, and hapten characterization has generally been poor or non-existent. In the present study, novel haptens of zearalenone with longer linkers and with alternative tethering sites have been designed for immunizing and assay conjugate preparation. All of these molecules were purified and spectroscopically verified, and a structure-activity relationship evaluation was carried out. This approach revealed that the hapten with the linker at the carbonyl group generated antibodies with a higher affinity than the hapten functionalized at the phenyl moiety. Antibodies produced with the latter hapten, on the other hand, showed lower cross-reactivity values to the major zearalenone metabolites. Finally, similar immunoassay sensitivity was achieved with all of the antibodies when heterologous haptens were employed. Furthermore, by altering the structure of the competing antigen, the immunoassay selectivity was modified. These results demonstrate that immunochemical methods for zearalenone rapid analysis can still be improved in terms of sensitivity and selectivity.

La presente invención se refiere a bioconjugados y derivados marcados de los aductos formados por la reacción de patulina con benceno-1,2-ditioles o sus sales. Dichos conjugados resultan adecuados para la producción de anticuerpos capaces de reconocer con elevada afinidad y especificidad los mencionados aductos patulina-(benceno-1,2-ditioles). Asimismo, la presente invención también se refiere al uso de bioconjugados dé los aductos patulina-(benceno-1,2-ditioles) y de derivados marcados de los mismos como antigenos de ensayo. Además, la presente invención también se refiere a métodos inmunoquímicos de análisis de patulina, utilizando los bioconjugados y derivados marcados y anticuerpos de la invención, que incluyen un paso previo para convertir cuantitativamente la patulina en estos aductos. Esta invención también proporciona un kit para analizar patulina que comprende un benceno-1,2-ditiol o sus sales, anticuerpos frente a los aductos patulina--(benceno-1,2-ditioles), y antígenos de ensayo. [ES], The present invention relates to bioconjugates and labeled derivatives of the adducts formed by the reaction of patulin with benzene-1,2-dithiols or their salts. Said conjugates are suitable for the production of antibodies capable of recognizing the aforementioned patulin-(benzene-1,2-dithiol) adducts with high affinity and specificity. Likewise, the present invention also relates to the use of bioconjugates of patulin-(benzene-1,2- dithiol) adducts and of labeled derivatives thereof as assay antigens. Furthermore, the present invention also relates to immunochemical methods for the analysis of patulin, using the bioconjugates and labeled derivatives and antibodies of the invention, which include a previous step to convert patulin quantitatively into these adducts. This invention also provides a kit for analyzing patulin comprising a benzene-1,2-dithiol or its salts, antibodies against patulin-(benzene-1,2-dithiol) adducts, and assay antigens. [EN]

Bioconjugados y anticuerpos para la inmunodetección asistida por derivatización de la micotoxina patulina. La presente invención se refiere a bioconjugados y derivados marcados de los aductos formados por la reacción de patulina con benceno-1,2-ditioles o sus sales. Dichos conjugados resultan adecuados para la producción de anticuerpos capaces de reconocer con elevada afinidad y especificidad los mencionados aductos patulina-(benceno-1,2-ditioles). Asimismo, la presente invención también se refiere al uso de bioconjugados de los aductos patulina- (benceno-1,2-ditioles) y de derivados marcados de los mismos como antígenos de ensayo. Además, la presente invención también se refiere a métodos inmunoquímicos de análisis de patulina, utilizando los bioconjugados y derivados marcados y anticuerpos de la invención, que incluyen un paso previo para convertir cuantitativamente la patulina en estos aductos. Esta invención también proporciona un kit para analizar patulina que comprende un benceno-1,2-ditiol o sus sales, anticuerpos frente a los aductos patulina-(benceno-1,2-ditioles), y antígenos de ensayo.

[ES] La presente invención se refiere a bioconjugados y derivados marcados de los aductos formados por la reacción de patulina con benceno-1,2-ditioles o sus sales. Dichos conjugados resultan adecuados para la producción de anticuerpos capaces de reconocer con elevada afinidad y especificidad los mencionados aductos patulina-(benceno-1,2-ditioles). Asimismo, la presente invención también se refiere al uso de bioconjugados de los aductos patulina- (benceno-1,2-ditioles) y de derivados marcados de los mismos como antígenos de ensayo. Además, la presente invención también se refiere a métodos inmunoquímicos de análisis de patulina, utilizando los bioconjugados y derivados marcados y anticuerpos de la invención, que incluyen un paso previo para convertir cuantitativamente la patulina en estos aductos. Esta invención también proporciona un kit para analizar patulina que comprende un benceno-1,2-ditiol o sus sales, anticuerpos frente a los aductos patulina-(benceno-1,2-ditioles), y antígenos de ensayo., [EN] The present invention relates to bioconjugates and labeled derivatives of the adducts formed by the reaction of patulin with benzene-1,2-dithiols or their salts. Said conjugates are suitable for the production of antibodies capable of recognizing with high affinity and specificity the aforementioned patulin-(benzene-1,2-dithiols) adducts. Likewise, the present invention also relates to the use of bioconjugates of patulin- (benzene-1,2-dithiols) adducts and labeled derivatives thereof as test antigens. Furthermore, the present invention also relates to immunochemical methods for the analysis of patulin, using the bioconjugates and labeled derivatives and antibodies of the invention, which include a previous step to quantitatively convert patulin into these adducts. This invention also provides a kit for testing patulin comprising a benzene-1,2-dithiol or its salts, antibodies to patulin- (benzene-1,2-dithiols) adducts, and test antigens.

Immunoassays are nowadays being employed for rapid contaminant analysis in clinical, environmental, and agrochemical samples. A thorough characterization of the antibody‒antigen interaction can bring light to the immunoreagent selection process in order to develop sensitive and robust tests. Thus, determination of equilibrium and reaction rate constants is usually recommendable. However, this can be quite tricky for low molecular weight compounds, and competitive strategies are commonly followed to estimate apparent affinity values. In the present study, a collection of monoclonal antibodies to penthiopyrad was raised for the first time, and apparent equilibrium constants were assessed by the Langmuir model using three different competitive enzyme-linked immunosorbent assay formats. The obtained KD values from antibody-coated assays were quite close to the corresponding KD values calculated from surface plasmon resonance (SPR) evaluation. These studies were employed to select a pair of immunoreagents for immunoassay development. The KD value for penthiopyrad of the selected antibody obtained by SPR was 0.28 nM. The optimized direct assay showed an IC50 value for penthiopyrad of 0.42 nM (0.15 ng mL−1) in buffer. The limit of quantification for grape, must, and wine samples was 10 ng mL−1. An excellent correlation was found when immunochemical results were compared with those from LC-MS/MS. As an application case, it was determined that 58% of penthiopyrad was still found in wine after fermentation.

Immunochemical methods for mycotoxin analysis require antigens with well-defined structures and antibodies with outstanding binding properties. Immunoreagents for the mycotoxins alternariol and/or alternariol monomethyl ether have typically been obtained with chemically uncharacterized haptens, and antigen conjugates have most likely been prepared with mixtures of functionalized molecules. For the first time, total synthesis was performed, in the present study, to obtain two haptens with opposite linker attachment locations. The functionalized synthetic haptens were purified and deeply characterized by different spectrometric methods, allowing the preparation of bioconjugates with unequivocal structures. Direct and indirect competitive enzyme-linked immunosorbent assays, using homologous and heterologous conjugates, were employed to extensively evaluate the generated immunoreagents. Antibodies with high affinity were raised from conjugates of both haptens, and a structure-activity relationship between the synthetic haptens and the specificity of the generated antibodies could be established. These results pave the way for the development of novel highly sensitive immunoassays selective of one or two of these Alternaria mycotoxins.

Mycotoxins represent a major concern for human and animal health because of their harmful effects and high occurrence in food and feed. Rapid immunoanalytical methods greatly contribute to strengthening the safety of our food supply by efficiently monitoring chemical contaminants, so high-affinity and specific antibodies have been generated for almost all internationally regulated mycotoxins. The only exception is patulin, a mycotoxin mainly produced by Penicillium expansum for which such a target has not yet been achieved. Accordingly, no point-of-need tests commonly used in food immunodiagnostics are commercially available for patulin. In the present study, three functionalized derivatives conforming to generally accepted rules in hapten design were firstly tested to generate suitable antibodies for the sensitive immunodetection of patulin. However, these conventional bioconjugates were unable to elicit the desired immune response, so an alternative strategy that takes advantage of the high electrophilic reactivity of patulin was explored. Patulin was reacted with 4-bromothiophenol, and the obtained adduct was used to produce antibodies with nanomolar affinity values. These results demonstrated for the first time that targeting the adduct resulting from the reaction of patulin with a thiol-containing compound is a promising approach for developing user-friendly immunoanalytical techniques for this elusive mycotoxin.

[ES] La presente invención se refiere a bioconjugados de análogos fragmentarios de aflatoxinas que tienen propiedades novedosas hacia los anticuerpos producidos frente a bioconjugados de aflatoxina M1. Asimismo, la presente invención también se refiere al uso de estos bioconjugados y derivados marcados de estos análogos fragmentarios como antígenos de ensayo. Además, la presente invención también se refiere a métodos de análisis utilizando estos bioconjugados o derivados marcados junto a anticuerpos producidos frente a aflatoxina M1. Esta invención también proporciona un kit para analizar aflatoxina M1 que comprende conjugados o derivados marcados de estos derivados fragmentarios junto con anticuerpos producidos frente a aflatoxina M1., [EN] The present invention relates to bioconjugates of fragmentary analogues of aflatoxins having novel properties towards antibodies produced against Aflatoxin bioconjugates M1. Likewise, the present invention also relates to the use of these bioconjugates and marked derivatives of these fragmentary analogues such as test antigens. In addition, the present invention also relates to methods of analysis using these bioconjugates or derivatives marked together with antibodies produced against aflatoxin M1. This invention also provides a kit for analyzing M1 aflatoxin comprising conjugates or marked derivatives of these fragmentary derivatives together with antibodies produced against aflatoxin M1.

[ES] La presente invención se refiere a bioconjugados de análogos fragmentarios de aflatoxinas que tienen propiedades novedosas hacia los anticuerpos producidos frente a bioconjugados de aflatoxina M1. Asimismo, la presente invención también se refiere al uso de estos bioconjugados y derivados marcados de estos análogos fragmentarios como antígenos de ensayo. Además, la presente invención también se refiere a métodos de análisis utilizando estos bioconjugados o derivados marcados junto a anticuerpos producidos frente a aflatoxina M1. Esta invención también proporciona un kit para analizar aflatoxina M1 que comprende conjugados o derivados marcados de estos derivados fragmentarios junto con anticuerpos producidos frente a aflatoxina M1., [EN] Bioconjugates heterologous and their use for the immunodetection of aflatoxins. The present invention relates to bioconjugates of fragmentary analogues of aflatoxins having novel properties towards antibodies produced against Aflatoxin bioconjugates M1. Likewise, the present invention also relates to the use of these bioconjugates and marked derivatives of these fragmentary analogues such as test antigens. In addition, the present invention also relates to methods of analysis using these bioconjugates or derivatives marked together with antibodies produced against aflatoxin M1. This invention also provides a kit for analyzing M1 aflatoxin comprising conjugates or marked derivatives of these fragmentary derivatives together with antibodies produced against aflatoxin M1.

Immunochemical methods are highly deployed in analytical laboratories worldwide for monitoring the incidence of mycotoxins in the food chain. Nevertheless, most conventional immunoassays for ochratoxin A (OTA), including commercial kits, show limitations to robustly determine this mycotoxin in grape-derived products below regulated levels (2 ng/mL). Herein, two rapid tests for sensitive OTA determination in wine and must were developed capitalizing on a collection of bioconjugates from innovative synthetic haptens and monoclonal antibodies with subnanomolar affinity. The ELISA (LOD = 8 pg/mL) showed excellent performance in recovery studies, and it was applied to survey commercial wines and musts for OTA contamination. Concerning LFIA, validation according to the Commission Regulation 519/2014 showed that samples exceeding 2 ng/mL were properly scored as uncompliant. More importantly, illegal samples provided a complete inhibition of the test signal, making this test an easy-to-use, rapid, and convenient screening method for in-house control of OTA in wineries.

Approximately 32 million people have died of HIV infection since the beginning of the outbreak, and 38 million are currently infected. Among strategies adopted by the Joint United Nations Programme on HIV/AIDS to end the AIDS global epidemic, the treatment, diagnosis, and viral suppression of the infected subjects are considered crucial for HIV prevention and transmission. Although several antiretroviral (ARV) drugs are successfully used to manage HIV infection, their efficacy strictly relies on perfect adherence to the therapy, which is seldom achieved. Patient supervision, especially in HIV-endemic, low-resource settings, requires rapid, easy-to-use, and affordable analytical tools, such as the enzyme-linked immunosorbent assay (ELISA) and especially the lateral flow immunoassay (LFIA). In this work, high-affinity monoclonal antibodies were generated to develop ELISA and LFIA prototypes for monitoring tenofovir (TFV), an ARV drug present in several HIV treatments. TFV was functionalized by inserting a carboxylated C5-linker at the phosphonic group of the molecule, and the synthetic derivative was conjugated to proteins for mice immunization. Through a rigorous screening strategy of hybridoma supernatants, a panel of monoclonal antibodies strongly binding to TFV was obtained. Following antibody characterization for affinity and selectivity by competitive ELISA, a LFIA prototype was developed and tentatively applied to determine TFV in simulated urine. The point-of-care test showed ultra-high detectability (the visual limit of detection was 2.5 nM, 1.4 ng mL−1), excellent selectivity, and limited proneness to matrix interference, thus potentially making this rapid method a valuable tool for the on-site assessment of patient adherence to ARV therapy.

[ES] El control efectivo de la calidad y seguridad de los ali­mentos requiere de métodos analíticos que garanticen la deter­minación fiable de cualquier sustancia potencialmente perjudicial para el consumidor que pueda estar presente en el alimento antes de su distribución y comercialización. Una de las aproximaciones analíticas que contribuye a garantizar este objetivo engloba una serie de técnicas que tienen en común la utilización de anticuerpos como elementos esenciales para la detección del analito diana, y que en conjunto reciben el nombre de métodos inmunoquímicos. Este artículo pretender aportar una visión básica de los principios bioquímicos subyacentes a estas tecnologías y cuáles son sus venta­jas y limitaciones en la determinación de contaminantes químicos, residuos y aditivos en matrices alimentarias. En la última parte se comentan algunas de nuestras iniciativas en este ámbito que han dado lugar a kits rápidos disponibles comercialmente tras haber transferido la tecnología correspondiente al sector industrial.

Bioorthogonal reactions have revolutionized the way low molecular weight compounds are coupled to biomolecules. Organic chemistry, polymer science, and chemical biology are among the disciplines that are benefited the most from this breakthrough. Despite the reliability of the click chemistry concept for the efficient and chemoselective functionalization of biomacromolecules with haptens at preferred positions, the fact that azide–alkyne cycloaddition reactions originate new chemical moieties as part of the linker may have delayed their application in the immunodiagnostic field. Using the mycotoxin ochratoxin A as a model compound, we herein demonstrate for the first time that bioconjugates arising from the ligation between an azido-bearing hapten and an alkyne-modified carrier protein are able to elicit the generation of high-affinity monoclonal antibodies suitable for the development of rapid methods for the immunodetection of small organic molecules.

A direct competitive immunosensor for the electrochemical determination of Imidacloprid (IMD) pesticide on gold nanoparticle-modified screen-printed carbon electrodes (AuNP-SPCE) is here reported for the first time. Self-obtained specific monoclonal antibodies are immobilized on the AuNP-SPCE taking advantage of the AuNPs biofunctionalization abilities. In our biosensor design, free IMD in the sample competes with IMD conjugated with horseradish peroxidase (IMD-HRP) for the recognition by the antibodies. After that, 3,3′,5,5′-Tetramethylbenzidine (TMB) is enzymatically oxidized by HRP, followed by the oxidized TMB reduction back at the surface of the SPCE. This process gives an associated catalytic current (analytical signal) that is inversely proportional to the IMD amount. The main parameters affecting the analytical signal have been optimized, reaching a good precision (repeatability with a RSD of 6%), accuracy (relative error of 6%), stability (up to one month), selectivity and an excellent limit of detection (LOD of 22 pmol L−1), below the maximum levels allowed by the legislation, with a wide response range (50–10000 pmol L−1). The detection through antibodies also allows to have an excellent selectivity against other pesticides potentially present in real samples. Low matrix effects were found when analysing IMD in tap water and watermelon samples. The electrochemical immunosensor was also validated with HPLC-MS/MS, the reference method used in official laboratories for IMD analysis, through statistical tests. Our findings make the electrochemical immunosensor as an outstanding method for the rapid and sensitive determination of IMD at the point-of-use.

Early warning systems for monitoring toxic events may benefit from the availability of monoclonal antibodies enabling the sensitive and specific detection of anatoxin‐a, a cyanotoxin involved in numerous cases of animal poisoning due to toxic algal blooms in freshwaters. Through the synthesis of three functionalized derivatives of anatoxin‐a, we have succeeded in generating the first‐ever reported immunoreagents (bioconjugates and antibodies) suitable for the development of immunoanalytical approaches aimed at rapid and onsite detection of this harmful cyanotoxin.

Monoclonal antibody-based techniques have become a useful analytical technology in the agro-food sector. Nowadays, residues of the recently registered fungicide fluopyram are increasingly being found in quality control programs. In the present study, novel chemical derivatives of this pesticide were prepared and specific and high-affinity monoclonal antibodies to fluopyram were raised for the first time. Moreover, immunoassays to fluopyram were developed in two alternative enzyme-linked immunosorbent assay formats, using homologous and heterologous assay conjugates, with limits of detection below 0.05 µg L−1. The optimized immunoassays were applied to the analysis of fluopyram in fortified plums and grapes of four different varieties as well as in in-house prepared musts and wines. Recoveries were between 76.3% and 109.6% and coefficients of variation were below 20%. Quantification limits were well below the maximum residue limits. Immunoassay performance was statistically validated with a reference chromatographic technique using samples from fluopyram-treated plum and grape cultivars.

La presente invención se refiere a bioconjugados y derivados marcados de ocratoxina A por posiciones diferentes de la molécula, adecuados para la producción de anticuerpos de elevada afinidad para ocratoxina A. Asimismo, la presente invención también se refiere al uso de bioconjugados de ocratoxina A y de derivados marcados de ocratoxina A como antígenos de ensayo. Además, la presente invención también se refiere a métodos de análisis, concentración y extracción de ocratoxina A utilizando los anticuerpos obtenidos, en ocasiones junto con antígenos de ensayo que son bioconjugados o derivados marcados. Esta invención también proporciona un kit para analizar ocratoxina A que comprende anticuerpos frente a esta micotoxina, en ocasiones junto con antígenos de ensayo que son bioconjugados o derivados de la ocratoxina A

The present invention relates to bioconjugates and derivatives of ochratoxin A labelled at different positions in the molecule suitable for the production of antibodies with a high affinity for ochratoxin A. Moreover, the present invention also relates to the use of ochratoxin A bioconjugates and labelled ochratoxin A derivatives as test antigens. The present invention also relates to methods for the analysis, concentration and extraction of ochratoxin A using the antibodies obtained, together with test antigens that are bioconjugates or labelled derivatives. This invention also provides a kit for analysing ochratoxin A comprising antibodies against said mycotoxin, in certain cases together with test antigens that are bioconjugates or labelled derivatives of ochratoxin A. [EN], La presente invención se refiere a bioconjugados y derivados marcados de ocratoxina A por posiciones diferentes de la molécula, adecuados para la producción de anticuerpos de elevada afinidad para ocratoxina A. Asimismo, la presente invención también se refiere al uso de bioconjugados de ocratoxina A y de derivados marcados de ocratoxina-A como antígenos de ensayo. Además, la presente invención también se refiere a métodos de análisis, concentración y extracción de ocratoxina A utilizando los anticuerpos obtenidos, en ocasiones junto con antígenos de ensayo que son bioconjugados o derivados marcados. Esta invención también proporciona un kit para analizar ocratoxina A que comprende anticuerpos frente a esta micotoxina, en ocasiones junto con antígenos de ensayo que son bioconjugados o derivados marcados de la ocratoxina A. [ES]

La presente invención se refiere a bioconjugados y derivados marcados de ocratoxina A por posiciones diferentes de la molécula, adecuados para la producción de anticuerpos de elevada afinidad para ocratoxina A. Asimismo, la presente invención también se refiere al uso de bioconjugados de ocratoxina A y de derivados marcados de ocratoxina A como antígenos de ensayo. Además, la presente invención también se refiere a métodos de análisis, concentración y extracción de ocratoxina A utilizando los anticuerpos obtenidos, en ocasiones junto con antígenos de ensayo que son bioconjugados o derivados marcados. Esta invención también proporciona un kit para analizar ocratoxina A que comprende anticuerpos frente a esta micotoxina, en ocasiones junto con antígenos de ensayo que son bioconjugados o derivados de la ocratoxina A.

Spirotetramat - a tetramic acid insecticide - is rapidly metabolized or degraded to give spirotetramat-enol; so, common residue definitions include the sum of both compounds. In the present study, two spirotetramat-functionalized derivatives (haptens) have been designed to generate immunoreagents to these molecules for rapid immunochemical analysis. Haptens have been synthesized with alternative linker tethering sites and, for the first time, high-affinity antibodies have been generated with different specificities to these active principles. Two sensitive assays have been developed using the same antibody in different formats, and by using linker-site heterologous haptens, the selectivity of the final immunoassay could be improved. A generic immunoassay with sensitivity similar to spirotetramat and spirotetramat-enol and a specific assay of spirotetramat-enol have been developed. The described antibody and bioconjugates showed great potential for sensitive immunosensor development and analysis of this complex analyte.

Ochratoxin A is a potent toxic fungal metabolite whose undesirable presence in food commodities constitutes a problem of public health, so it is strictly regulated and controlled. For the first time, two derivatives of ochratoxin A (OTAb and OTAd) functionalized through positions other than the native carboxyl group of the mycotoxin, have been synthesized in order to better mimic, during the immunization process, the steric and conformational properties of the target analyte. Additionally, two conventional haptens making use of that native carboxyl group for protein coupling (OTAe and OTAf) were also prepared as controls for the purpose of comparison. The immunological performance in rabbits of protein conjugates based on OTAb and OTAd overcome that of conjugates employing OTAe and OTAf as haptens. After immunization of mice with OTAb and OTAd conjugates, a collection of high-affinity monoclonal antibodies to ochratoxin A was generated. In particular, one of those antibodies, the so-called OTAb#311, is very likely the best antibody produced so far in terms of selectivity and affinity to ochratoxin A.

Nowadays, instrumental methodologies and rapid bioanalytical techniques complement each other for the analysis of toxic chemical compounds. Fluxapyroxad was commercialized a few years ago as a fungicide and today it is being used worldwide to control a variety of pests. In the present study, the development of monoclonal antibody-based immunochemical methods for the analysis of this chemical in food samples was evaluated for the first time. Novel haptens were synthesized and protein bioconjugates were prepared. High-affinity and specific monoclonal antibodies to fluxapyroxad were generated from two haptens with alternative linker tethering sites. Haptens with linker site heterology and a structurally heterologous hapten with a minor modification of the molecule conformation and volume but with a significant alteration of the electronic density of the pyrazole moiety were evaluated for immunoassay development. Direct and indirect competitive immunoassays were characterized and optimized, showing IC50 values for fluxapyroxad of 0.14 and 0.05 ng mL−1, respectively. The combination of two heterologies was particularly adequate in the indirect format. The two developed immunoassays showed excellent recoveries and coefficients of variation in fluxapyroxad-fortified plums and four varieties of grapes. Finally, a good correlation was found between the indirect immunoassay and UPLC-MS/MS when fruit samples with incurred residues of fluxapyroxad were analyzed. These monoclonal antibody-based immunochemical methods hold great promise for fluxapyroxad monitoring.

Immunochemical methods have been consolidated during the last few years as complementary analytical strategies for chemical contaminant and residue determination. However, generation of suitable immunoreagents for small organic molecules demands adequate hapten design. In this study, fenhexamid was considered as a model compound and novel haptens were designed and synthesized in order to evaluate the influence of the linker tethering site on antibody binding properties and immunoassay parameters. Haptens were conceived with the spacer arm at different positions, while the more antigenic aromatic moiety was kept free. The synthesis of these functionalized compounds was accomplished by total construction of the molecule through several steps. This strategy afforded very high-affinity monoclonal antibodies specific of fenhexamid, with IC50 values around or below 0.1 nM. Using these novel immunoreagents, a direct competitive enzyme-linked immunosorbent assay with a remarkably low limit of detection (4 ng L−1) was developed for the determination of fenhexamid residues. The selected immunoassay was investigated in terms of trueness, precision, repeatability, and robustness. The QuEChERS extraction methodology was applied to fortified samples and recoveries between 83% and 113%, with relative standard deviations below 20%, were observed. Moreover, contaminated and blind spiked samples were measured by the developed immunoassay and by ultra-performance liquid chromatography coupled to tandem mass spectrometry, showing statistically comparable results.

Boscalid is an agrochemical recently developed for crop protection and the most significant member of the succinate dehydrogenase inhibitor group of fungicides. In this study, a collection of high-affinity monoclonal antibodies was generated to boscalid. By using a series of haptens with a linker at alternative tethering sites of the boscalid framework, specific antibodies were isolated as well as antibodies that also recognized the main boscalid metabolite. Two immunoassays were developed using different ELISA formats. Optimized assays displayed very high sensitivities (limits of detection were near 0.01 µg/L). Trueness and precision for the determination of the target analyte in strawberry samples was evaluated. Moreover, immunoassay performance was validated with a reference chromatographic method using QuEChERS extracts of fruits from fungicide-treated crops. A monitoring study with strawberry samples from local markets was carried out by immunoassay, showing an occurrence of boscalid of 15% with a maximum residue concentration of 43 µg/kg.

[ES] Preparación de bioconjugados y anticuerpos para la inmunodetección de anatoxina-a. La presente invención se refiere a bioconjurados y derivados marcados de anatoxina-a, por posiciones diferentes de la molécula, adecuados para la producción de anticuerpos de elevada afinidad y especificidad para anatoxina-a. Asimismo, la presente invención ta,bién se refiere al uso de bioconjurados de anatoxina-a y de derivados marcados de anatoxina-a como antígenos de ensayo. Además, la presente invención también se refiere a métodos de análisis, concentración y extracción de anatoxina-a utilizando los anticuerpos obtenidos, en ocasiones junto con antígenos de ensayo que son bioconjurados o derivados de marcados. Esta invención también proporciona un kit para analizar anatoxina-a que comprende anticuerpos frente a esta cianotoxina, en ocasiones junto con antígenos de ensayo que son bioconjugados o derivados marcados de la anatoxina-a., [EN] The present invention relates to bioconjugates and labeled derivatives of anatoxin-a, at different positions of the molecule, suitable for producing antibodies with high affinity and specificity for anatoxin-a. At the same time, the present invention also relates to the use of bioconjugates of anatoxin-a and labeled derivatives of anatoxin-a as assay antigens. Moreover, the present invention also relates to methods for analyzing, concentrating and extracting anatoxin-a using the antibodies obtained, sometimes together with assay antigens which are bioconjugates or labeled derivatives. This invention also provides a kit for analyzing anatoxin-a which comprises antibodies against this cyanotoxin sometimes together with assay antigens which are bioconjugates or labeled derivatives of anatoxin-a.

[EN] The present invention relates to bioconjugates and labeled derivatives of anatoxin-a, at different positions of the molecule, suitable for producing antibodies with high affinity and specificity for anatoxin-a. At the same time, the present invention also relates to the use of bioconjugates of anatoxin-a and labeled derivatives of anatoxin-a as assay antigens. Moreover, the present invention also relates to methods for analyzing, concentrating and extracting anatoxin-a using the antibodies obtained, sometimes together with assay antigens which are bioconjugates or labeled derivatives. This invention also provides a kit for analyzing anatoxin-a which comprises antibodies against this cyanotoxin sometimes together with assay antigens which are bioconjugates or labeled derivatives of anatoxin-a., [ES] Preparación de bioconjugados y anticuerpos para la inmunodetección de anatoxina-a. La presente invención se refiere a bioconjurados y derivados marcados de anatoxina-a, por posiciones diferentes de la molécula, adecuados para la producción de anticuerpos de elevada afinidad y especificidad para anatoxina-a. Asimismo, la presente invención ta,bién se refiere al uso de bioconjurados de anatoxina-a y de derivados marcados de anatoxina-a como antígenos de ensayo. Además, la presente invención también se refiere a métodos de análisis, concentración y extracción de anatoxina-a utilizando los anticuerpos obtenidos, en ocasiones junto con antígenos de ensayo que son bioconjurados o derivados de marcados. Esta invención también proporciona un kit para analizar anatoxina-a que comprende anticuerpos frente a esta cianotoxina, en ocasiones junto con antígenos de ensayo que son bioconjugados o derivados marcados de la anatoxina-a.

[ES] Preparación de bioconjugados y anticuerpos para la inmunodetección de anatoxina-a. La presente invención se refiere a bioconjurados y derivados marcados de anatoxina-a, por posiciones diferentes de la molécula, adecuados para la producción de anticuerpos de elevada afinidad y especificidad para anatoxina-a. Asimismo, la presente invención ta,bién se refiere al uso de bioconjurados de anatoxina-a y de derivados marcados de anatoxina-a como antígenos de ensayo. Además, la presente invención también se refiere a métodos de análisis, concentración y extracción de anatoxina-a utilizando los anticuerpos obtenidos, en ocasiones junto con antígenos de ensayo que son bioconjurados o derivados de marcados. Esta invención también proporciona un kit para analizar anatoxina-a que comprende anticuerpos frente a esta cianotoxina, en ocasiones junto con antígenos de ensayo que son bioconjugados o derivados marcados de la anatoxina-a., [EN] The present invention relates to bioconjugates and labeled derivatives of anatoxin-a, at different positions of the molecule, suitable for producing antibodies with high affinity and specificity for anatoxin-a. At the same time, the present invention also relates to the use of bioconjugates of anatoxin-a and labeled derivatives of anatoxin-a as assay antigens. Moreover, the present invention also relates to methods for analyzing, concentrating and extracting anatoxin-a using the antibodies obtained, sometimes together with assay antigens which are bioconjugates or labeled derivatives. This invention also provides a kit for analyzing anatoxin-a which comprises antibodies against this cyanotoxin sometimes together with assay antigens which are bioconjugates or labeled derivatives of anatoxin-a.

[EN] The present invention relates to bioconjugates and labeled derivatives of anatoxin-a, at different positions of the molecule, suitable for producing antibodies with high affinity and specificity for anatoxin-a. At the same time, the present invention also relates to the use of bioconjugates of anatoxin-a and labeled derivatives of anatoxin-a as assay antigens. Moreover, the present invention also relates to methods for analyzing, concentrating and extracting anatoxin-a using the antibodies obtained, sometimes together with assay antigens which are bioconjugates or labeled derivatives. This invention also provides a kit for analyzing anatoxin-a which comprises antibodies against this cyanotoxin sometimes together with assay antigens which are bioconjugates or labeled derivatives of anatoxin-a., [ES] Preparación de bioconjugados y anticuerpos para la inmunodetección de anatoxina-a. La presente invención se refiere a bioconjurados y derivados marcados de anatoxina-a, por posiciones diferentes de la molécula, adecuados para la producción de anticuerpos de elevada afinidad y especificidad para anatoxina-a. Asimismo, la presente invención ta,bién se refiere al uso de bioconjurados de anatoxina-a y de derivados marcados de anatoxina-a como antígenos de ensayo. Además, la presente invención también se refiere a métodos de análisis, concentración y extracción de anatoxina-a utilizando los anticuerpos obtenidos, en ocasiones junto con antígenos de ensayo que son bioconjurados o derivados de marcados. Esta invención también proporciona un kit para analizar anatoxina-a que comprende anticuerpos frente a esta cianotoxina, en ocasiones junto con antígenos de ensayo que son bioconjugados o derivados marcados de la anatoxina-a.

[ES] Preparación de bioconjugados y anticuerpos para la inmunodetección de anatoxina-a. La presente invención se refiere a bioconjurados y derivados marcados de anatoxina-a, por posiciones diferentes de la molécula, adecuados para la producción de anticuerpos de elevada afinidad y especificidad para anatoxina-a. Asimismo, la presente invención ta,bién se refiere al uso de bioconjurados de anatoxina-a y de derivados marcados de anatoxina-a como antígenos de ensayo. Además, la presente invención también se refiere a métodos de análisis, concentración y extracción de anatoxina-a utilizando los anticuerpos obtenidos, en ocasiones junto con antígenos de ensayo que son bioconjurados o derivados de marcados. Esta invención también proporciona un kit para analizar anatoxina-a que comprende anticuerpos frente a esta cianotoxina, en ocasiones junto con antígenos de ensayo que son bioconjugados o derivados marcados de la anatoxina-a., [EN] The present invention relates to bioconjugates and labeled derivatives of anatoxin-a, at different positions of the molecule, suitable for producing antibodies with high affinity and specificity for anatoxin-a. At the same time, the present invention also relates to the use of bioconjugates of anatoxin-a and labeled derivatives of anatoxin-a as assay antigens. Moreover, the present invention also relates to methods for analyzing, concentrating and extracting anatoxin-a using the antibodies obtained, sometimes together with assay antigens which are bioconjugates or labeled derivatives. This invention also provides a kit for analyzing anatoxin-a which comprises antibodies against this cyanotoxin sometimes together with assay antigens which are bioconjugates or labeled derivatives of anatoxin-a.

New-generation succinate dehydrogenase inhibitors with increased antifungal performance have been developed during the last years. Particularly, penthiopyrad has been recently introduced in the agrochemical market as a complementary fungicide for combined treatments with other active principles displaying a different mode of action. In the present study, rapid and high-throughput analytical methods for penthiopyrad residue determination in foodstuffs were developed. A novel functionalized hapten that completely mimics the molecule of penthiopyrad was designed for high-affinity and specific antibody generation. Moreover, heterologous haptens were synthesized, and the influence of their respective molecular modifications over antibody binding was evaluated by competitive enzyme-linked immunosorbent assay. Two immunoassays were optimized using alternative assay formats, affording limits of detection for penthiopyrad in buffer around 0.07 ng/mL in both cases. Performance, in terms of accuracy and precision, of the developed immunochemical methods was studied using apple juice and red and white grape juices. The obtained results showed that penthiopyrad could be determined in those food samples in compliance with European maximum residue limits.

A fluopyram hapten was designed in which insignificant electronic and structural modifications were foreseen and all potentially interacting chemical moieties were maintained. This hapten was prepared by total synthesis and three immunologically active bioconjugates were obtained and characterized. High-affinity and specific antibodies to fluopyram were raised.

Bioconjugate preparation is a fundamental step for antibody generation and immunoassay development to small chemical compounds. For analytical targets holding in their structure an aryl halogen atom, cross-coupling reactions may be a simple and efficient way to obtain functionalized derivatives; thus offering great potential to elicit robust and selective immune responses after being coupled to immunogenic carrier proteins. However, substitution of the halogen atom by an aliphatic chain might eventually compromise the affinity and specificity of the resulting antibodies. In order to address this issue, proquinazid, a new-generation fungicide with outstanding performance, was chosen as model analyte. Two functionalized derivatives differing in spacer arm rigidity were synthesized by Sonogashira cross-coupling chemistry. These haptens were covalently coupled to bovine serum albumin and the resulting immunoconjugates were employed for rabbit vaccination. Antibodies were tested for proquinazid recognition by direct and indirect competitive immunoassay, and IC50 values in the low nanomolar range were found, thus demonstrating the suitability of this straightforward synthetic strategy for the generation of immunoreagents to compounds bearing an aryl halide. Following antibody characterization, competitive immunoassays were developed and employed to determine proquinazid residues in grape musts, and their analytical performance was satisfactorily validated by comparison with GC–MS. Besides having described the development of the first immunochemical method for proquinazid analysis, an efficient functionalization approach for analytes comprising aryl halides is reported.

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.

[EN] The invention relates to haptenes, conjugates, marked derivates and antibodies for fludioxonil. The invention also relates to the use of conjugates of fludioxonil as test antigens or immunogens for producing antibodies of said fungicide; and to the use of the marked derivatives of fludioxonil as test antigens. The invention further relates to a method for analysing fludioxonil using the antibodies produced, sometimes together with test antigens that are conjugates or marked derivatives. The invention also provides a kit for analysing fludioxonil comprising antibodies of said fungicide, sometimes together with test antigens that are conjugates or marked derivatives, [ES] La presente invención se refiere a haptenos, conjugados, derivados marcados y anticuerpos para fludioxonil. Así mismo, la presente invención también se refiere al uso de conjugados de fludioxonil como antígenos de ensayo o inmunógenos para obtener anticuerpos de este fungicida; y al uso de los derivados marcados de fludioxonil como antígenos de ensayo. Además, la presente invención también se refiere a un método de análisis de fludioxonil utilizando los anticuerpos obtenidos, en ocasiones junto con antígenos de ensayo que son conjugados o derivados marcados. Esta invención también proporciona un kit para analizar fludioxonil que comprende anticuerpos de este fungicida, en ocasiones junto con antígenos de ensayo que son conjugados o derivados marcados

La presente invención se refiere a haptenos, conjugados, derivados marcados y anticuerpos para fludioxonil. Asímismo, la presente invención también se refiere al uso de conjugados de fludioxonil como antígenos de ensayo o inmunógenos para obtener anticuerpos de este fungicida; y al uso de los derivados marcados de fludioxonil como antígenos de ensayo. Además, la presente invención también se refiere a un método de análisis de fludioxonil utilizando los anticuerpos obtenidos, en ocasiones junto con antígenos de ensayo que son conjugados o derivados marcados. Esta invención también proporciona un kit para analizar fludioxonil que comprende anticuerpos de este fungicida, en ocasiones junto con antígenos de ensayo que son conjugados o derivados marcados

La presente invención se refiere a haptenos, conjugados, derivados marcados y anticuerpos para fludioxonil. Asímismo, la presente invención también se refiere al uso de conjugados de fludioxonil como antígenos de ensayo o inmunógenos para obtener anticuerpos de este fungicida; y al uso de los derivados marcados de fludioxonil como antígenos de ensayo. Además, la presente invención también se refiere a un método de análisis de fludioxonil utilizando los anticuerpos obtenidos, en ocasiones junto con antígenos de ensayo que son conjugados o derivados marcados. Esta invención también proporciona un kit para analizar fludioxonil que comprende anticuerpos de este fungicida, en ocasiones junto con antígenos de ensayo que son conjugados o derivados marcados

Trifloxystrobin is one of the main active principles belonging to the strobilurin family of crop protection compounds. In this article, the synthesis of a battery of regioisomeric functionalized derivatives of trifloxystrobin is described. The same aliphatic linear carboxylated chain was introduced as spacer arm in all of the synthesized haptens, but it was located at different positions of the parent molecule. N,N′-Disuccinimidyl carbonate was employed for hapten activation, so the resulting N-hydroxysuccinimyl ester could be readily purified and efficiently coupled to proteins. After immunization and hybridoma generation, a collection of 20 mouse monoclonal antibodies from different immunizing haptens was obtained. The analytical performance of these immunoreagents was evaluated in terms of affinity and selectivity with the aim to develop rapid and practical immunochemical procedures for trifloxystrobin determination. © 2013 Elsevier Ltd. All rights reserved.

Haptens, bioconjugates, and antibodies for highly sensitive immunochemical analysis of the new-generation fungicide penthiopyrad are described. Two haptens with equivalent carboxylated linkers were prepared, and the purified active esters were efficiently coupled to proteins. The results revealed slightly different antibody-eliciting capacities for the two synthetic derivatives. All of the produced antibodies were specific for penthiopyrad, and showed affinity values in the nanomolar range.

Kresoxim-methyl was one of the two first strobilurins to be discovered, and nowadays it is widely used as an antifungal agent in crop protection. Because of its low molecular weight and negligible structural complexity, the generation of antibodies to kresoxim-methyl noticeably requires the preparation of functionalized haptens. In this study, the introduction of a hydrocarbon spacer arm at the aromatic moieties of the target molecule was carried out by a convergent strategy based on the Sonogashira cross-coupling reaction, and functionalized linkers of the same length were also tethered to the aliphatic toxophore group by the O-alkylation reaction. Evaluation of the immune response, in terms of antibody affinity, showed a differential behavior among five synthesized haptens whose sole dissimilarity was the derivatization site. The characteristic (methoxyimino)acetate moiety of strobilurins was revealed as the optimum linker position for high-affinity polyclonal and monoclonal antibody production. However, good monoclonal antibodies were isolated from mice immunized with a hapten carrying the linker at an opposite site, which otherwise generated a poor polyclonal response in rabbits. Site-heterology was confirmed as a feasible approach for the improvement of the apparent affinity, particularly with polyclonal antibodies. Several of the monoclonal antibodies generated in the context of this project could be proper binders for kresoxim-methyl immunosensing over different analytical platforms.

Strobilurins are a family of synthetic natural-derived pesticides widely used for fungi control in many crops. As part of a larger research project, a collection of monoclonal antibodies to one of the most relevant strobilurins, i.e. pyraclostrobin, has been generated using functionalized haptens with the spacer arm located at different sites. The toxophore aliphatic moiety, as observed with other strobilurins, and the planar aromatic two-ring system characteristic of this molecule were revealed as the best tethering sites for high-affinity monoclonal antibody production. A central derivatization position did not generate a good immune response, but such derivatives were useful as heterologous competitors in order to improve assay sensitivity. Direct and indirect assays were characterized in terms of solvent influence, pH, and ionic strength. Immunoassays with limits of detection below 0.1 οg/L were developed. A QuEChERS-based procedure was applied to the extraction of blueberry, strawberry, raspberry, peach, apricot, and plum jams. Clean acetonitrile extracts were properly diluted in water and analyzed by both optimized immunoassays with good accuracy and precision at levels covering the European maximum residue limits for those fruits. © 2012 Elsevier Ltd.

Rapid analytical methods enabling the determination of diverse targets are essential in a number of research areas, from clinical diagnostics to feed and food quality and safety. Herein, the development of a quantitative immunochromatographic assay for the detection of the synthetic phytoregulator forchlorfenuron (CPPU) is described. The competitive lateral flow immunoassay (LFIA) was based on the immobilization onto a nitrocellulose membrane of an ovalbumin-CPPU conjugate (test line) and on the use of an immunodetection ligand consisting of carbon nanoparticles labeled with an anti-CPPU monoclonal antibody through interaction with a secondary antibody. The presence of CPPU in horticultural samples was visually interpreted by the decrease in the black signal intensity of the test line, according to the competitive character of the format. The quantitative determination of the analyte was easily performed by a two-step procedure consisting of flatbed scanning of the strips followed by computer-based image analysis of the pixel gray volumes of the test lines. Under optimized conditions, the immunochromatographic test afforded a limit of quantification in buffer of 89. ng/L. The accuracy of the strip test was assessed by the analysis of fruit samples with incurred residues, and the obtained results were compared with those derived from two reference methods, ELISA and HPLC. The LOQ of the CPPU-specific LFIA in kiwifruits and grapes was established at 33.4 οg/kg. The excellent analytical performance of the developed strip test demonstrates the potential of immunochromatographic assays for the quantitative monitoring of small organic molecules in complex matrices. © 2012 Elsevier B.V.

Mepanipyrim is an anilinopyrimidine fungicide used worldwide for crop protection. With the aim of developing useful immunoreagents for mepanipyrim immunoanalysis, two new functionalized derivatives were prepared and antibodies were generated. Affinity and specificity were assessed by direct and indirect competitive ELISA using homologous and heterologous conjugates. Although all antibodies were selective for the target analyte, the immunizing hapten structure was revealed as a determinant for high-affinity antibody production (IC50 = 3 nM). © 2013 The Royal Society of Chemistry.

Quantum dots (QDs) are semiconductor nanoparticles with very interesting optical properties, like high quantum yield or narrow and size-tuneable fluorescence spectra. Current applications of QDs are widespread, their use as fluorescence labels in bioassays being one of the most promising. These nanoparticles are usually conjugated to highly specific biomolecules like antibodies, oligonucleotides, enzymes or aptamers to improve assay selectivity. In this review, QD surface passivation, conjugation to biomolecules, and purification strategies are discussed with special emphasis to the development of QD-based immunoassays for the detection of low molecular weight compounds given the relevance of this sort of analytes in health, food safety, pharmaceutical, or environmental monitoring areas. The aim of this review is to summarise the main achievements attained so far and to initialise researchers in the field of antibody-based assays employing QDs as labels, such as fluorescence-linked immunosorbent assay (FLISA), fluorescence (or Förster) resonance energy transfer (FRET), immunochromatographic methods, and immunosensors.

La presente invención se refiere a haptenos, conjugados, derivados marcados y anticuerpos para ciprodinil. Así mismo, la presente invención también se refiere al uso de conjugados de ciprodinil como antígenos de ensayo o inmunógenos para obtener anticuerpos de este fungicida; y al uso de los derivados marcados de ciprodinil como antígenos de ensayo. Además, la presente invención también se refiere a un método de análisis de ciprodinil utilizando los anticuerpos obtenidos, en ocasiones junto con antígenos de ensayo que son conjugados o derivados marcados. Esta invención también proporciona un kit para analizar ciprodinil que comprende anticuerpos de este fungicida, en ocasiones junto con antígenos de ensayo que son conjugados o derivados marcados.