Highly Sensitive Lateral Flow Immunodetection of the Insecticide Imidacloprid in Fruits and Berries Reached by Indirect Antibody-Label Coupling.

A highly sensitive lateral flow immunoassay (LFIA) for imidacloprid, a widely used neonicotinoid insecticide, has been developed. The LFIA realizes the indirect coupling of anti-imidacloprid antibodies and gold nanoparticle (GNP) labels directly in the course of the assay. For this purpose, the common GNPs conjugate with anti-imidacloprid antibodies and are changed into a combination of non-modified, anti-imidacloprid antibodies, and the GNPs conjugate with anti-species antibodies.

Lateral Flow Immunosensing of Typhimurium Cells in Milk: Comparing Three Sequences of Interactions.

To ensure the safety of foodstuffs, widespread non-laboratory monitoring for pathogenic contaminants is in demand. A suitable technique for this purpose is lateral flow immunoassay (LFIA) which combines simplicity, rapidity, and productivity with specific immune detection. This study considered three developed formats of LFIA for Typhimurium, a priority pathogenic contaminant of milk.

Highly Targeted Detection of Priority Phytopathogen : From Obtaining Polyclonal Antibodies to Development and Approbation of Enzyme-Linked Immunoassay and Lateral Flow Immunoassay.

is a bacterial phytopathogen that causes soft and black rot and actively spreads worldwide. Our study is the first development of immunoassays for detecting . We immunized rabbits and obtained serum with an extremely high titer (1:10).

Ultrasensitive Lateral Flow Immunoassay of Fluoroquinolone Antibiotic Gatifloxacin Using Au@Ag Nanoparticles as a Signal-Enhancing Label.

Gatifloxacin (GAT), an antibiotic belonging to the fluoroquinolone (FQ) class, is a toxicant that may contaminate food products. In this study, a method of ultrasensitive immunochromatographic detection of GAT was developed for the first time. An indirect format of the lateral flow immunoassay (LFIA) was performed.

SERS Sensors with Bio-Derived Substrates Under the Way to Agricultural Monitoring of Pesticide Residues.

Uncontrolled use of pesticides in agriculture leads to negative consequences for the environment, as well as for human and animal health. Therefore, timely detection of pesticides will allow application of measures to eliminate the excess of maximum residue limits and reduce possible negative consequences in advance. Common methods of pesticide analysis suffer from high costs, and are time consuming, and labor intensive.

Comparison of Conjugates Obtained Using DMSO and DMF as Solvents in the Production of Polyclonal Antibodies and ELISA Development: A Case Study on Bisphenol A.

When developing immunochemical test systems, it is necessary to obtain specific antibodies. Their quality depends, among other things, on the immunogen used. When preparing hapten-protein conjugates to obtain antibodies for low-molecular-weight compounds, the key factors are the structure of the hapten itself, the presence of a spacer, the size of the carrier protein and the degree of its modification by hapten molecules.

Evaluation of amplicons by AF4 as assistant for deep comprehension of loop-mediated isothermal amplification combined with lateral flow assay.

Loop-mediated isothermal amplification (LAMP) is a rapid and efficient method for DNA amplification, producing concatemers of varying lengths (amplicons). This study explores the characterization of LAMP amplicons using asymmetric flow field-flow fractionation (AF4) and their realization in LAMP - lateral flow assay (LFA) for point-of-care diagnostics. We examined LAMP products from the invA gene of Salmonella enterica using two specific primer sets and three methods: fluorescent staining with SYBR Green, electrophoretic detection, and AF4.

Comparative Characteristics of Immunochromatographic Test Systems for Tylosin Antibiotic in Meat Products.

Tylosin (TYL) is a macrolide antibiotic widely used in animal husbandry. Due to associated health risks, there is a demand for sensitive methods for mass screening of TYL in products of animal origin. This article describes the development of lateral flow immunoassays (LFIAs) for TYL detection using direct (anti-TYL antibodies conjugated with nanoparticles) and indirect antibody labeling (anti-species antibodies conjugated with nanoparticles and combined with native anti-TYL antibodies).

Dual lateral flow test for simple and rapid simultaneous immunodetection of bisphenol A and dimethyl phthalate, two priority plastic related environmental contaminants.

Contamination of the environment by technogenic endocrine disrupting compounds (EDCs) becomes serious threat to public health. To effectively prevent this threat, it is necessary to improve analytical methods for EDCs to ensure mass, fast and productive monitoring. In the given work, a dual lateral flow test (LFT) is developed in the first time for simultaneous immunodetection of bisphenol A and dimethyl phthalate, priority EDCs releasing from plastic and belonging to different chemical classes.

Prussian-Blue-Nanozyme-Enhanced Simultaneous Immunochromatographic Control of Two Relevant Bacterial Pathogens in Milk.

and are relevant foodborne bacterial pathogens which may cause serious intoxications and infectious diseases in humans. In this study, a sensitive immunochromatographic analysis (ICA) for the simultaneous detection of these two pathogens was developed. For this, test strips containing two test zones with specific monoclonal antibodies (MAb) against lipopolysaccharides of and and one control zone with secondary antibodies were designed, and the double-assay conditions were optimized to ensure high analytical parameters.

Freeze-Driven Adsorption of Oligonucleotides with polyA-Anchors on Au@Pt Nanozyme.

A promising and sought-after class of nanozymes for various applications is Pt-containing nanozymes, primarily Au@Pt, due to their easy preparation and remarkable catalytic properties. This study aimed to explore the freeze-thaw method for functionalizing Pt-containing nanozymes with oligonucleotides featuring a polyadenine anchor. Spherical gold nanoparticles ([Au]NPs) were synthesized and subsequently used as seeds to produce urchin-like Au@Pt nanoparticles ([Au@Pt]NPs) with an average diameter of 29.

Polycations as Aptamer-Binding Modulators for Sensitive Fluorescence Anisotropy Assay of Aflatoxin B1.

Fluorescence induced by the excitation of a fluorophore with plane-polarized light has a different polarization depending on the size of the fluorophore-containing reagent and the rate of its rotation. Based on this effect, many analytical systems have been implemented in which an analyte contained in a sample and labeled with a fluorophore (usually fluorescein) competes to bind to antibodies. Replacing antibodies in such assays with aptamers, low-cost and stable oligonucleotide receptors, is complicated because binding a fluorophore to them causes a less significant change in the polarization of emissions.

Double lateral flow immunosensing of undeclared pork and chicken components of meat products.

Unlabelled: Adulteration of meat products is a serious problem in the modern society. Consumption of falsified meat products can be hazardous to health and/or lead to violating religious dietary principles. To identify such products, rapid and simple test systems for point-of-need detection are in demand along with complex laboratory methods.

Comparison of competitive and sandwich immunochromatographic analysis in the authentication of chicken in meat products.

Cheap chicken meat is often used as an undeclared substitute in meat products. In this study, two formats of the immunochromatographic assay (ICA) of immunoglobulins of class Y (IgY) as a biomarker for chicken authentication were developed. In both competitive ICA (cICA) and sandwich ICA (sICA), gold nanoparticles (GNP) were conjugated with anti-species antibodies.

Highly Sensitive Immunochromatographic Detection of Porcine Myoglobin as Biomarker for Meat Authentication Using Prussian Blue Nanozyme.

This study was aimed at the sensitive immunodetection of porcine myoglobin (MG) as a species-specific biomarker in meat products. The enhanced lateral flow immunoassay (LFIA) was created in the sandwich format using monoclonal antibodies (Mab) with specificity to porcine MG and labeled by Prussian blue nanoparticles (PBNPs) as peroxidase-mimicking nanozymes. Signal amplification was provided by the colored product of oxidation catalyzed by the PBNPs.

Sensitive immunoenzyme assay for the detection of antibiotic flumequine in honey.

Fluoroquinolone antibiotics are used to cure and protect bees and apiaries from infections. Consequently, they may contaminate honey and other products of beekeeping. In this study, a highly sensitive immunoenzyme assay (EIA) was for the first time developed for the determination of a fluoroquinolone flumequine (FLU) in honey.

DNA Probes for Cas12a-Based Assay with Fluorescence Anisotropy Enhanced Due to Anchors and Salts.

CRISPR/Cas12a is a potent biosensing tool known for its high specificity in DNA analysis. Cas12a recognizes the target DNA and acquires nuclease activity toward single-stranded DNA (ssDNA) probes. We present a straightforward and versatile approach to transforming common Cas12a-cleavable DNA probes into enhancing tools for fluorescence anisotropy (FA) measurements.

Ability of Antibodies Immobilized on Gold Nanoparticles to Bind Small Antigen Fluorescein.

The analytical applications of antibodies are often associated with their immobilization on different carriers, which is accompanied by a loss of antigen-binding activity for a sufficient proportion of the bound antibodies. In contrast to data on plain carriers, minimal data are available on the properties of antibodies on the surfaces of nanoparticles. Protein antigens have been predominantly investigated, for which space restrictions do not allow them to occupy all active sites of immobilized antibodies.

A Fluorescence Resonance Energy Transfer Aptasensor for Aflatoxin B1 Based on Ligand-Induced ssDNA Displacement.

In this study, a fluorescence resonance energy transfer (FRET)-based aptasensor for the detection of aflatoxin B1 (AFB1) was designed using a carboxyfluorescein (FAM)-labeled aptamer and short complementary DNA (cDNA) labeled with low molecular quencher RTQ1. The sensing principle was based on the detection of restored FAM-aptamer fluorescence due to the ligand-induced displacement of cDNA in the presence of AFB1, leading to the destruction of the aptamer/cDNA duplex and preventing the convergence of FAM and RTQ1 at the effective FRET distance. Under optimal sensing conditions, a linear correlation was obtained between the fluorescence intensity of the FAM-aptamer and the AFB1 concentration in the range of 2.

Sensitive Immunochromatographic Determination of in Food Products Using Au@Pt Nanozyme.

In this study, we developed a sensitive immunochromatographic analysis (ICA) of the bacterial pathogen contaminating food products and causing foodborne illness. The ICA of was performed using Au@Pt nanozyme as a label ensuring both colorimetric detection and catalytic amplification of the analytical signal due to nanozyme peroxidase-mimic properties. The enhanced ICA enabled the detection of cells with the visual limit of detection (LOD) of 2 × 10 CFU/mL, which outperformed the LOD in the ICA with traditional gold nanoparticles by two orders of magnitude.

Sensitive Silver-Enhanced Microplate Apta-Enzyme Assay of Sb Ions in Drinking and Natural Waters.

The toxic effects of antimony pose risks to human health. Therefore, simple analytical techniques for its widescale monitoring in water sources are in demand. In this study, a sensitive microplate apta-enzyme assay for Sb detection was developed.

Post-Assay Chemical Enhancement for Highly Sensitive Lateral Flow Immunoassays: A Critical Review.

Lateral flow immunoassay (LFIA) has found a broad application for testing in point-of-care (POC) settings. LFIA is performed using test strips-fully integrated multimembrane assemblies containing all reagents for assay performance. Migration of liquid sample along the test strip initiates the formation of labeled immunocomplexes, which are detected visually or instrumentally.

A Critical Study on DNA Probes Attached to Microplate for CRISPR/Cas12 Trans-Cleavage Activity.

CRISPR/Cas12-based biosensors are emerging tools for diagnostics. However, their application of heterogeneous formats needs the efficient detection of Cas12 activity. We investigated DNA probes attached to the microplate surface and cleaved by Cas12a.

Comparison of Three Lateral Flow Immunoassay Formats for the Detection of Antibodies against the SARS-CoV-2 Antigen.

Reliable detection of specific antibodies against pathogens by lateral flow immunoassay (LFIA) greatly depends on the composition of the detectable complex and the order of its assembly. We compared three LFIA formats for revealing anti-SARS-CoV-2 antibodies in sera with the following detected complexes in the analytical zone of the strip: antigen-antibodies-labeled immunoglobulin-binding protein (Scheme A); antigen-antibodies-labeled antigen (Scheme B); and immunoglobulin-binding protein-antibodies-labeled antigen (Scheme C). The lowest detection limit was observed for Scheme C, and was equal to 10 ng/mL of specific humanized monoclonal antibodies.