Papers by Anatoly Zherdev
Bioanalytical Technologies for Safety Control of Fish and Seafood by Sensitive Rapid Tests for Phycotoxins
IOP conference series, Feb 1, 2022
Wide and operate safety monitoring of foodstuffs is highly demanded in modern society. This work ... more Wide and operate safety monitoring of foodstuffs is highly demanded in modern society. This work aims to develop and characterize new test systems for control of phycotoxins, dangerous contaminants of fish and seafood. For rapid and productive testing, 2 methods have been implemented: immunochromatographic assay and fluorescence polarization immunoassay. Various approaches for reducing the limit of detection of target analytes have been considered, including changes in the use of optical and fluorescent labels and varied order of the detected complexes formation. Antibodies and aptamers have been considered as receptor molecules. The developed techniques provide rapid (20–30 minutes, including sample preparation) and sensitive testing. Their effectiveness has been shown for different kinds of fish and seafood. Portable detectors have been proposed that allow testing directly at the sampling points, without transportation to centralized laboratories.
Analytical Letters, Apr 14, 2019
The paper describes the first use of silanized semiconductor coreshell quantum dots as fluorescen... more The paper describes the first use of silanized semiconductor coreshell quantum dots as fluorescent labels for macromolecule, C-reactive protein determination in blood plasma. The controlled synthesis of CdSe cores, with successive shells of CdS, CdZnS, ZnS and coating with transparent, stable, and inert silica shell, provides quantum dots with a narrow emission band, high quantum yield, and prolonged signal stability. Finally, the quantum dots were conjugated with specific antibodies via carboxylic groups on the silica surface. The method was further used for the immunochromatographic assay of C-reactive protein, a diagnostically important inflammatory biomarker. Assays with both the fluorescent QDs and a widely used colloidal gold label were developed in parallel and compared. The silanized quantum dots provide a more sensitive assay with a detection limit of 1 ng/mL for C-reactive protein in standard solutions, whereas the common assay has a detection limit of 10 ng/mL. The possibility of quantitative evaluation of analyte content by a portable device was demonstrated; the accuracy of the measurements was in the range of 5%-10%. The tests were used to determine C-reactive proteins in human plasma samples. The selected optimized protocol for these samples is based on a 4-fold dilution. The final working range of the assay, 4-1,200 ng/mL, covers practically all important interval of C-reactive protein values for the characterization of acute, chronic, and local inflammatory processes. Due to their high physical stability and inertness as well as intense, stable, and reproducible fluorescence, silanized quantum dots may be applied for high-sensitive assays for different analytes.
Аналитика и контроль, 2019
Одной из основных проблем современного производства мясных продуктов является качество мясного сы... more Одной из основных проблем современного производства мясных продуктов является качество мясного сырья, которое зависит от разных факторов, включая генетические составляющие, условия транспортирования, производства и переработки. К наиболее значимым компонентам мяса относятся белки, общее содержание, структура и функциональное состояние которых в составе этой сложной биологической системы, с большим количеством взаимодействующих составляющих, постоянно изменяется. Для изучения межвидовых и внутривидовых особенностей белков мяса, трансформации их в процессе созревания и технологической обработки требуются современные аналитические технологии, основанные на системном подходе к анализу. Широкие возможности в этом направлении открывает протеомика, как методологии изучения белков в определенной системе и в определенное время, позволяющая идентифицировать и разрабатывать точные аналитические методы поиска биомаркеров и выявления недобросовестных практик. Учитывая высокую добавленную стоимость и многокомпонентность состава, готовые мясные продукты относятся к числу наиболее подверженных фальсификации. В работе представлена методика высокоэффективной жидкостной хроматографии с масс-спектрометрическим детектором (ВЭЖХ-МС), адаптированная для обнаружения и количественного определения двух различных видов мяса (говядина и свинина) в сложной биологической матрице, такой как бесструктурные фарши. После выделения белков и расщепления их трипсином были выбраны видоспецифичные пептидные маркеры для каждого вида животного с целью количественного определения. Методика была апробирована на модельных образцах смеси мышечной ткани двух видов животных. Установлена хорошая чувствительность с возможностью количественного определения мышечной ткани каждого вида животного, при использовании специальных градуировочных графиков. Разработанная методика может найти широкое применение у контролирующих организаций, направленных на противодействие несоответствиям по скрытой замене видов мяса более дешевым или низкосортными сырьем.
Biosensors, Apr 16, 2023
In this study, a homogeneous fluorescence polarization immunoassay (FPIA) for the detection of ha... more In this study, a homogeneous fluorescence polarization immunoassay (FPIA) for the detection of hazardous aquatic toxin okadaic acid (OA) contaminating environmental waters was for the first time developed. A conjugate of the analyte with a fluorophore based on a fluorescein derivative (tracer) was synthesized, and its interaction with specific anti-OA monoclonal antibodies (MAbs) was tested. A MAbs-tracer pair demonstrated highly affine immune binding (KD = 0.8 nM). Under optimal conditions, the limit of OA detection in the FPIA was 0.08 ng/mL (0.1 nM), and the working range of detectable concentrations was 0.4-72.5 ng/mL (0.5-90 nM). The developed FPIA was approbated for the determination of OA in real matrices: river water and seawater samples. No matrix effect of water was observed; therefore, no sample preparation was required before analysis. Due to this factor, the entire analytical procedure took less than 10 min. Using a compact portable fluorescence polarization analyzer enables the on-site testing of water samples. The developed analysis is very fast, easy to operate, and sensitive and can be extended to the determination of other aquatic toxins or low-molecular-weight water or food contaminants.
Potravinarstvo, Oct 28, 2021
Because of the increased demand for processed meat, there is an urgent need to introduce specific... more Because of the increased demand for processed meat, there is an urgent need to introduce specific identification methods. Strategies such as molecular genetics and the physical condition of meat are used to quickly explore multi-component products. However, a single methodology does not always unambiguously classify a product as counterfeit. In laboratory practice, as a rule, screening techniques are rarely used in the first stage, followed by arbitration. This work aimed to study individual methodologies using artificially falsified meat samples as examples and to identify their composition based on muscle tissue. For the experiments, the three most common types of raw meat were selected: pork, beef, and chicken. The calculation of the content of muscle tissue was carried out according to the BEFFE method. The study of muscle protein was carried out by ICA, ELISA, PCR, microstructural analysis, and mass spectrometric identification. In this connection, we proposed a multilevel control system for multicomponent meat products. Both classical methodologies, such as calculation by prescription bookmarks (BEFFE) and microstructural analysis, and approaches of highly sensitive methodologies, such as identification of muscle tissue by marker peptides (LC/MS-MRM) and semi-quantitative PCR analysis, were evaluated.
Analytical Application of Lectins
Critical Reviews in Analytical Chemistry, Feb 8, 2018
ABSTRACT This review is devoted to the analytical application of carbohydrate-binding proteins ca... more ABSTRACT This review is devoted to the analytical application of carbohydrate-binding proteins called lectins. The nature of lectins and the regularities of their specificity with respect to simple sugars and complex carbohydrate-containing biomolecules are discussed. The main areas of the modern analytical application of lectins are described. Lectin-affinity chromatography, histo- and cytochemical approaches, lectin blotting, microarray, and biosensor technologies as well as microplate analysis are considered in detail. Data on the use of lectins for the detection of cells and microorganisms as well as the study of protein glycosylation are summarized. The large potential of lectins as components of analytical systems used for the identification of glycans and the characteristics of their structure are substantiated.
Highly sensitive technologies of molecular dyagnosis of potato viruse and viroid infections
Current Research in Nutrition and Food Science Journal, 2020
Violations in manufacturing and products that do not meet the declared markings are currently an ... more Violations in manufacturing and products that do not meet the declared markings are currently an acute problem in ensuring the safety and quality of food. Meat products are often falsified due to the high added value and multicomponent composition. Despite the efforts of regulatory organizations, the covert replacement of various types of meat with cheaper or low-grade compounds is widespread. Consumer societies, individuals, food quality control state institutions are interested in the results of food quality, safety and conformity monitoring. This article presents information on results of food products’ conformity and possible analytical methods used to control meat products’ composition, the results of meat product monitoring as conducted by the V. M. Gorbatov Federal National Center for Food Systems (Moscow, Russia), data on the prevalence of various types of falsification, and proposals to improve the quality and safety control of meat products in Russia. According to the nati...
[Simple immunoassays of pesticides based on the biotin-streptavidin system]
Bioorganicheskaia khimiia, 1997
A simple method was developed for the preparation of a highly active streptavidin-peroxidase conj... more A simple method was developed for the preparation of a highly active streptavidin-peroxidase conjugate that enhances fourfold the sensitivity of bioassays. Using this conjugate, a quantitative assay of simazine and 2,4-dichlorophenoxyacetic acid (competitive ELISA) and a noninstrumental express method for simultaneous detection of these pesticides (dot-immunofiltration assay) were developed. The detection limit of the pesticides is 3-4 and 2 ng/ml and the duration of the assays is 1.5 h and 5 min for ELISA and dot-immunofiltration, respectively. The express method is easy and straightforward and enables the assay to be performed outside the laboratory.
CSAC 2023
Immunochromatographic tests are of particular interest as tools for monitoring toxic environmenta... more Immunochromatographic tests are of particular interest as tools for monitoring toxic environmental pollutants. In this regard, the aim of this study was to develop an immunochromatographic test system for the detection of surfactant nonylphenol in water. Two schemes of the assay were compared; they are characterized by detection limits of 1.1 and 0.4 µg/mL and recoveries of nonylphenol from spring water in the range of 78-113.7%.
Analytical Biochemistry, Dec 1, 2015
Nanodispersed gold is widely used as a marker in different analytical systems. For such purposes ... more Nanodispersed gold is widely used as a marker in different analytical systems. For such purposes it is usually obtained by the reduction of salts. This work studies the potential analytical applications of nanodispersed gold obtained by laser ablation, as gold produced with this method has no chemical coating. The nanoparticles produced were characterized by transmission electron microscopy and spectrophotometry. The average size of the particles was 24.5 nm. Concentration dependences of antibody immobilization on ablative gold were obtained. With the use of antibody-conjugated nanoparticles, an immunochromatographic system was constructed for the detection of zearalenone mycotoxin. This immunoassay was characterized by a detection limit of 0.1 ng/mL antigen with an assay duration of only 15 minutes, which is on par with current test systems comprising nanodispersed gold obtained by chemical reduction. The simplicity of ablative dispersing makes this a prospective method for the labeling of various antibodies for analytical use.
Micromachines, Sep 10, 2022
In this investigation, a double immunochromatographic analysis (ICA) of two relevant phycotoxins,... more In this investigation, a double immunochromatographic analysis (ICA) of two relevant phycotoxins, domoic acid (DA) and okadaic acid (OA), was developed for the first time. The ICA was performed in the indirect competitive format using gold nanoparticles conjugated with anti-species antibodies. Under optimal conditions, the instrumental detection limits/cutoffs for simultaneous detection of DA and OA were 1.2/100 and 0.1/2.5 ng/mL, respectively. The time of the assay was 18 min. The ICA was applied to test seawater and a large panel of seafood, including mussels, tiger shrimps, octopuses, whelks, crabs, and scallops. The proposed simple sample preparation method for seafood takes only 20 min. For seawater, a dilution by buffer was implemented. The assay recoveries varied from 80.8% to 124.5%. The competitive potential of the proposed technique as a tool to control natural water and seafood samples is determined by its simplicity, rapidity, and sensitivity.
We report the approach for the detection of Au@Pt core@shell nanoparticles (nanozymes) with perox... more We report the approach for the detection of Au@Pt core@shell nanoparticles (nanozymes) with peroxidase-mimicking activity (PMA) in samples with high endogenous peroxidase activity (EPA). Unlike the endogenous peroxidases in plant extracts that are inhibited by elevated H2O2 (>20 mM), the PMA of nanozymes was stable in concentrated H2O2 (up to 4 M). Such a different stability of enzymes and Au@Pt to the substrate allowed for eliminating EPA and detecting only nanozymes. The developed approach was used for reaching a lower limit of detection (LOD) and eliminating the background for the lateral flow immunoassay (LFIA) of the important plant pathogen potato virus X (PVX) in leaf and tuber extracts. Using the PMA of Au@Pt, the LOD was reduced to 4 and 8 pg/mL in tuber and leaf extracts, respectively. The LOD values are 250-and 500-times lower in comparison with LFIA with conventional gold nanoparticles. The developed approach of peroxidases inhibition is universal for bioanalytical methods, and its applicability was confirmed by the elimination of EPA in three matrixes (serum, potato leaf and tuber extracts).
Biosensors
Reliable detection of specific antibodies against pathogens by lateral flow immunoassay (LFIA) gr... more 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. When working with pooled positive sera, Scheme C had a detection limit 15 times lower than Scheme B and 255 times lower than Scheme A. Due to the high sensitivity of Scheme C, its application for the panel of human sera (n = 22) demonstrated 100% diagnostic specificity and sensitivity. These consistent results be useful for designing the...
Biosensors
Finding optimal conditions for competitive lateral flow immunoassay is a controversial task. The ... more Finding optimal conditions for competitive lateral flow immunoassay is a controversial task. The content of specific antibodies labeled by nanoparticles should be simultaneously high to reach intense signals and low to register an influence on the signals for minimal concentrations of the target analyte. We propose to use two kinds of complexes of gold nanoparticles in the assay, with antigen–protein conjugates and with specific antibodies. The first complex interacts both with immobilized antibodies in the test zone and with antibodies on the surface of the second complex. In this assay, the coloration is enhanced by the binding of two-colored preparations in the test zone, whereas the antigen in the sample inhibits both the binding of the first conjugate with the immobilized antibodies and with the second conjugate. This approach is realized for the detection of insecticide imidacloprid (IMD), an important toxic contaminant connected with the recent global death of bees. The propo...
Biosensors
A scheme of modular competitive immunochromatography with an analyte-independent test strip and c... more A scheme of modular competitive immunochromatography with an analyte-independent test strip and changeable specific immunoreactants has been proposed. Native (detected) and biotinylated antigens interact with specific antibodies during their preincubation in solution, that is, without the immobilization of reagents. After this, the detectable complexes on the test strip are formed by the use of streptavidin (which binds biotin with high affinity), anti-species antibodies, and immunoglobulin-binding streptococcal protein G. The technique was successfully applied for the detection of neomycin in honey. The visual and instrumental detection limits were 0.3 and 0.014 mg/kg, respectively, and the degree of neomycin revealed in honey samples varied from 85% to 113%. The efficiency of the modular technique with the use of the same test strip for different analytes was confirmed for streptomycin detection. The proposed approach excludes the necessity of finding the condition of immobilizati...
Biosensors
A new scheme of reagents interaction for lateral flow immunoassay (LFIA) is proposed, which combi... more A new scheme of reagents interaction for lateral flow immunoassay (LFIA) is proposed, which combines the features of competitive and sandwich assay and provides highly sensitive detection of low-molecular-weight analytes. Namely, the antigen in the sample interferes with the formation of the antibody (on the membrane)–hapten-protein–antibody (on the nanoparticle-marker) complex, competing with hapten-protein conjugate in both reactions. The proposed scheme was modelled using COPASI software, with a prediction of limit of detection (LOD) decrease by one order of magnitude compared to the standard competitive LFIA. This feature was experimentally confirmed for the detection of chloramphenicol (CAP) in honey. When tested in spiked honey, the visual LOD was 50 ng/mL for the common scheme and 5 ng/mL for the proposed scheme. Instrumental LOD was 300 pg/mL (1.2 µg/kg in conversion per sample weight of honey) in the standard scheme and 20 pg/mL (80 ng/kg in conversion per sample weight of ...
Micromachines
Changes in the limits of detection (LODs) for a multiplex lateral flow immunoassay (LFIA) caused ... more Changes in the limits of detection (LODs) for a multiplex lateral flow immunoassay (LFIA) caused by different locations of the binding zone on the test strips were studied. Due to the non-equilibrium conditions of the immune reactions in LFIAs, their analytical parameters are susceptible to the binding constants of antigen–antibody reactions and assay duration. Consequently, the integration of several tests into one multiplex assay can cause a significant worsening of the sensitivity. In this study, we propose a simple methodology for the determination of the best arrangement of binding zones, which takes into account the binding constants for immunoreagents. LFIAs of four mycotoxins, namely, aflatoxin B1, deoxynivalenol, T-2 toxin, and ochratoxin A, were integrated into a multiplex test strip. An enzyme-linked immunosorbent assay was applied to determine the equilibrium and kinetic constants of the immunoreactants for each analyte. It was found that the arrangement of binding zones...
Chemosensors
Mercury pollution is a global environmental problem, especially in low-resource areas where artis... more Mercury pollution is a global environmental problem, especially in low-resource areas where artisanal iron mining is taking place and industrialization is on the rise. Therefore, there is a demand for simple methods for the determination of toxic metals at low. In this study, an on-field membrane lateral flow test system for sensitive and specific detection of Hg2+ in natural waters matrix is proposed. For this purpose, mercaptosuccinic acid (MSA) conjugated with protein-carrier (bovine serum albumin) was pre-impregnated in the test zone of the strip and used as a capping agent for mercury complexation. Quantitative evaluation of the analyte was provided by the use of gold nanoparticles stabilized with Tween-20 as a detecting agent. The sensing principle relies on the formation of Au–Hg nanoalloy during the migration of a solution containing Hg2+ along the strip, followed by capture in the test zone with the formation of a colored complex. Under optimum conditions, the proposed late...
Journal of physics, Feb 1, 2022
Aptamers are single-stranded nucleic acids, typically 20-80 nucleobases (nb) in length, which can... more Aptamers are single-stranded nucleic acids, typically 20-80 nucleobases (nb) in length, which can bind different compounds with high affinity and selectively. Their ligandbinding properties can be attenuated by adding short complementary strands. These interactions open new opportunities for aptamer-based assays. Strong dependence between the length and electrophoretic mobility of short nucleic acids makes polyacrylamide gel electrophoresis a powerful tool for studying their complexes. The interactions between the 36 nb DNA G-quadruplex aptamer (5'-GAT-CGG-GTG-TGG-GTG-GCG-TAA-AGG-GAG-CAT-CGG-ACA-3') specific to ochratoxin A and 9 complementary single-stranded DNA (ssDNA) were studied. The length of ssDNA varied from 5 to 9 nb. To maintain ligand-binding conformation of the aptamer, a high ionic strength buffer was used. The best resolution between the aptamer and its complex was provided for the gel with 15% monomer and a monomer/cross-linker ratio of 15:1. Bands of free aptamer and ssDNA were observed for all studied variants. If the ssDNA length was less than 9 nb, the position of the aptamer's band remained unchanged, independent of the aptamer/ssDNA ratios, and additional bands did not appear. The longest ssDNA (5'-CGC-CAC-CCA-3') did not lead to the appearance of a new band, but it slowed the aptamer's migration depending on the ssDNA concentration. Under a 27-fold excess of the given ssDNA, the relative mobility of the aptamer band changed from 0.566 to 0.468. Thus, electrophoresis visualizes aptamer-ssDNA interactions and can be used in the development of aptamer-based analytical systems.
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Papers by Anatoly Zherdev