Development of Simple and Rapid Bead-Based Cytometric Immunoassays Using Superparamagnetic Hybrid Core-Shell Microparticles.

Flow cytometry-based immunoassays are valuable in biomedical research and clinical applications due to their high throughput and multianalyte capability, but their adoption in areas such as food safety and environmental monitoring is limited by long assay times and complex workflows. Rapid, simplified bead-based cytometric immunoassays are needed to make these methods viable for point-of-need applications, especially with the increasing accessibility of miniaturized cytometers. This work introduces superparamagnetic hybrid polystyrene-silica core-shell microparticles as promising alternatives to conventional polymer beads in competitive cytometric immunoassays.

Absolute Configuration of the Invasive Mealybug (De Lotto) Sex Pheromone: Synthesis and Bioassay of Both Enantiomers.

The mealybug (De Lotto) (Hemiptera: Pseudococcidae) is an invasive pest reported in Europe at the end of the first decade of the 2000s, causing severe damage to citrus production in eastern Spain. In a previous work, (4,5,5-trimethyl-3-methylenecyclopent-1-en-1-yl)methyl acetate was identified as the sex pheromone emitted by females, a new compound with an unusual β-necrodol skeleton possessing one stereocenter. This compound was assigned to the (-)-enantiomer but the absolute configuration was then not reported.

Harnessing the Intrinsic Chemical Reactivity of the Mycotoxin Patulin for Immunosensing.

Mycotoxins are globally pervasive contaminants that threaten food safety worldwide. Regulatory authorities have established maximum permissible levels for certain mycotoxins, and their presence is routinely monitored throughout the food chain to ensure the provision of healthy food and safe feed for humans and animals. While immunoanalytical methods are essential for mycotoxin screening, monoclonal antibodies for the detection of patulin are notably absent.

Rapid immunochemical methods for the analysis of proquinazid in strawberry QuEChERS extracts.

Proquinazid is a new-generation fungicide authorized in the EU for combating powdery mildew infections in high-value crops. Due to the perishable nature of fruits, alternative analytical methods are necessary to protect consumer's health from pesticide residues. Currently, immunoassays are a well-established approach for rapidly monitoring chemical contaminants.

New Monoterpenoid as the Sex Pheromone of Spanish Populations of the Longtailed Mealybug (Hemiptera: Pseudococcidae).

(Targioni-Tozzetti) (Hemiptera: Coccoidea: Pseudococcidae), a polyphagous and cosmopolitan pest native to Australia, is a highly damaging pest for numerous crops of economic importance. The sex pheromone of this species (2-(1,5,5-trimethylcyclopent-2-en-1-yl)ethyl acetate), currently used for pest monitoring purposes, was not attractive to males in field experiments conducted in Spanish persimmon orchards infested with this mealybug. The virgin and mated female volatile profiles of these populations were studied by the volatile collection of effluvia in Porapak-Q.

Sensitive and selective alternariol analysis by a newly developed monoclonal antibody-based immunoassay.

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.

Development and In-House Validation of an Enzyme-Linked Immunosorbent Assay and a Lateral Flow Immunoassay for the Dosage of Tenofovir in Human Saliva.

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.

Correction: Addante-Moya et al. Assessment of the Optimum Linker Tethering Site of Alternariol Haptens for Antibody Generation and Immunoassay Development. 2021, , 883.

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Design of a novel hapten and development of a sensitive monoclonal immunoassay for dicamba analysis in environmental water samples.

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.

Rapid Immunochemical Methods for Anatoxin-a Monitoring 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.

Alternative Hapten Design for Zearalenone Immunoreagent Generation.

Appropriate hapten design and synthesis have been identified as critical steps to generate 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.

Assessment of the Optimum Linker Tethering Site of Alternariol Haptens for Antibody Generation and Immunoassay Development.

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.

Chemical strategies for triggering the immune response to the mycotoxin patulin.

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.

Immunochemical method for penthiopyrad detection through thermodynamic and kinetic characterization of monoclonal antibodies.

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.

Enzyme and lateral flow monoclonal antibody-based immunoassays to simultaneously determine spirotetramat and spirotetramat-enol in foodstuffs.

Spirotetramat is employed worldwide to fight insect pests due to its high efficiency. This chemical is quickly metabolized by plants into spirotetramat-enol, so current regulations establish that both compounds must be determined in foodstuffs for monitoring purposes. Nowadays, immunochemical methods constitute rapid and cost-effective strategies for chemical contaminant analysis at trace levels.

Immunoanalytical methods for ochratoxin A monitoring in wine and must based on innovative immunoreagents.

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.

Monoclonal antibodies with subnanomolar affinity to tenofovir for monitoring adherence to antiretroviral therapies: from hapten synthesis to prototype development.

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.

Click Chemistry-Assisted Bioconjugates for Hapten Immunodiagnostics.

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 have 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.

Synthetic Haptens and Monoclonal Antibodies to the Cyanotoxin Anatoxin-a.

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 resulting from 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.

Highly sensitive monoclonal antibody-based immunoassays for the analysis of fluopyram in food samples.

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.

Combined heterologies for monoclonal antibody-based immunoanalysis of fluxapyroxad.

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.

Hapten Design and Antibody Generation for Immunoanalysis of Spirotetramat and Spirotetramat-enol.

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.

Immunochemical rapid determination of quinoxyfen, a priority hazardous pollutant.

In 2013, quinoxyfen was included in the list of priority hazard pollutants of the European Water Framework Directive due to its toxicity to aquatic organisms. However, few analytical methods for the analysis of this fungicide have been reported and no rapid immunochemical methods have been published so far. In the present study, immunoreagents for quinoxyfen analysis were generated for the first time and an enzyme-linked immunosorbent assay was developed.

Novel haptens and monoclonal antibodies with subnanomolar affinity for a classical analytical target, ochratoxin A.

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.

Highly sensitive monoclonal antibody-based immunoassays for boscalid analysis in strawberries.

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.