scholarly journals Biosensors for the Determination of SARS-CoV-2 Virus and Diagnosis of COVID-19 Infection

2022 ◽  
Vol 23 (2) ◽  
pp. 666
Author(s):  
Maryia Drobysh ◽  
Almira Ramanaviciene ◽  
Roman Viter ◽  
Chien-Fu Chen ◽  
Urte Samukaite-Bubniene ◽  
...  
Keyword(s):  
Current Trend ◽  
Analytical Signal ◽  
Diagnostic Methods ◽  
Detection Methods ◽  
Label Free ◽  
Free Mode ◽  
Rna Hybridisation ◽  
Antigen Antibody ◽  
Affinity Interaction

Monitoring and tracking infection is required in order to reduce the spread of the coronavirus disease 2019 (COVID-19), induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To achieve this goal, the development and deployment of quick, accurate, and sensitive diagnostic methods are necessary. The determination of the SARS-CoV-2 virus is performed by biosensing devices, which vary according to detection methods and the biomarkers which are inducing/providing an analytical signal. RNA hybridisation, antigen-antibody affinity interaction, and a variety of other biological reactions are commonly used to generate analytical signals that can be precisely detected using electrochemical, electrochemiluminescence, optical, and other methodologies and transducers. Electrochemical biosensors, in particular, correspond to the current trend of bioanalytical process acceleration and simplification. Immunosensors are based on the determination of antigen-antibody interaction, which on some occasions can be determined in a label-free mode with sufficient sensitivity.

scholarly journals Affinity Sensors for the Diagnosis of COVID-19

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 390
Author(s):  
Maryia Drobysh ◽  
Almira Ramanaviciene ◽  
Roman Viter ◽  
Arunas Ramanavicius
Keyword(s):  
Field Effect Transistors ◽  
Resonance Field ◽  
Analytical Signal ◽  
Nucleic Acid Hybridization ◽  
Detection Methods ◽  
Label Free ◽  
Infected People ◽  
Label Free Detection ◽  
Main Instrument ◽  
Antigen Antibody

The coronavirus disease 2019 (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was proclaimed a global pandemic in March 2020. Reducing the dissemination rate, in particular by tracking the infected people and their contacts, is the main instrument against infection spreading. Therefore, the creation and implementation of fast, reliable and responsive methods suitable for the diagnosis of COVID-19 are required. These needs can be fulfilled using affinity sensors, which differ in applied detection methods and markers that are generating analytical signals. Recently, nucleic acid hybridization, antigen-antibody interaction, and change of reactive oxygen species (ROS) level are mostly used for the generation of analytical signals, which can be accurately measured by electrochemical, optical, surface plasmon resonance, field-effect transistors, and some other methods and transducers. Electrochemical biosensors are the most consistent with the general trend towards, acceleration, and simplification of the bioanalytical process. These biosensors mostly are based on the determination of antigen-antibody interaction and are robust, sensitive, accurate, and sometimes enable label-free detection of an analyte. Along with the specification of biosensors, we also provide a brief overview of generally used testing techniques, and the description of the structure, life cycle and immune host response to SARS-CoV-2, and some deeper details of analytical signal detection principles.

scholarly journals Direct and Competitive Optical Grating Immunosensors for Determination of Fusarium Mycotoxin Zearalenone

Toxins ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 43
Author(s):  
Inna Székács ◽  
Nóra Adányi ◽  
István Szendrő ◽  
András Székács
Keyword(s):  
Environmental Safety ◽  
Detection Methods ◽  
Label Free ◽  
Detection Range ◽  
Fusarium Mycotoxin ◽  
Label Free Detection ◽  
Optical Grating ◽  
Covalent Immobilisation ◽  
Magnitude Improvement

Novel optical waveguide lightmode spectroscopy (OWLS)-based immunosensor formats were developed for label-free detection of Fusarium mycotoxin zearalenone (ZON). To achieve low limits of detection (LODs), both immobilised antibody-based (direct) and immobilised antigen-based (competitive) assay setups were applied. Immunoreagents were immobilised on epoxy-, amino-, and carboxyl-functionalised sensor surfaces, and by optimising the immobilisation methods, standard sigmoid curves were obtained in both sensor formats. An outstanding LOD of 0.002 pg/mL was obtained for ZON in the competitive immunosensor setup with a dynamic detection range between 0.01 and 1 pg/mL ZON concentrations, depending on the covalent immobilisation method applied. This corresponds to a five orders of magnitude improvement in detectability of ZON relative to the previously developed enzyme-linked immonosorbent assay (ELISA) method. The selectivity of the immunosensor for ZON was demonstrated with structural analogues (α-zearalenol, α-zearalanol, and β-zearalanol) and structurally unrelated mycotoxins. The method was found to be applicable in maize extract using acetonitrile as the organic solvent, upon a dilution rate of 1:10,000 in buffer. Thus, the OWLS immunosensor method developed appears to be suitable for the quantitative determination of ZON in aqueous medium. The new technique can widen the range of sensoric detection methods of ZON for surveys in food and environmental safety assessment.

Immunochemical methods for detection of organophosphorus compounds

2020 ◽  
pp. 219-230
Author(s):  
Sergey Eremin
Keyword(s):  
High Throughput Screening ◽  
Organophosphorus Compounds ◽  
High Sensitivity ◽  
Analytical Signal ◽  
Test System ◽  
Detection Methods ◽  
Environmental Objects ◽  
Immunochemical Test ◽  
Immunochemical Methods ◽  
Antigen Antibody

Organophosphorus compounds (OP) are found in environmental objects and food products. Due to their high toxicity and inhibition of cholinesterase activity, it is necessary to control residual amounts of OP. The most common methods for determining OP are gas and liquid chromatography with various detection methods. However, chromatographic analysis is lengthy, requires complex sample preparation and expensive equipment, which limits its use for screening a large number of samples and continuous monitoring of the content of OP. To detect the OP, it is necessary to use High Throughput Screening methods, using simple, fast and inexpensive analysis methods. Currently, immunochemical methods are increasingly used to determine OP. These methods are based on the recognition of the analyte (antigen) by specific receptors (antibodies) with the formation of the antigen-antibody complex and the measurement of the analytical signal generated by the immunochemical test system in response to complex formation, which leads to high sensitivity and specificity of the analysis.

EVALUATION OF HYSTEROSALPINGOGRAPHY VERSUS LAPAROSCOPY IN THE DETERMINATION OF TUBAL FACTORS IN FEMALE INFERTILITY: A HOSPITAL BASED COMPARATIVE STUDY.

2020 ◽  
Vol 4 (9) ◽  
Author(s):  
Richa Choudhary ◽  
Rishikant Sinha
Keyword(s):  
Female Infertility ◽  
Diagnostic Methods ◽  
Panoramic View ◽  
Tubal Patency ◽  
Pelvic Organs ◽  
Clinical Investigations ◽  
Detailed Assessment ◽  
Reproductive Anatomy ◽  
Tubal Pathology

Objectives: Hysterosalpingography and laparoscopy both are the diagnostic methods for assessment of female infertility.  The present study was to compare the evaluation of hysterosalpingography (HSG) versus laparoscopy in determination of tubal factors in female infertility. Methods: Detailed assessment, physical examination and clinical investigations were performed in all 100 infertile female with age 20 years to 40 years. All patients were advised to perform digital HSG. Patients with an abnormal HSG underwent laparoscopy without delay, whereas in patients with a normal HSG, laparoscopy was performed three months after HSG. HSG is best scheduled during the 2nd -5th day interval immediately following the end of menstruation, to minimize risk for infection, avoid interference from intrauterine blood and clot, and to prevent any possibility that the procedure might be performed after conception. Results: Data was analysed by using IBM SPSS version 23 software.  All data was tabulated and percentages were calculated. Mean ± standard deviation was observed. Conclusions: Diagnostic laparoscopy is the gold standard in diagnosing tubal pathology and other intra-abdominal causes of infertility. Other hand, Hysterosalpingography is a frequently utilized diagnostic tool in the assessment of tubal status and detection of uterine anatomical defects in infertility. Hysterosalpingography and laparoscopy are not alternatives but complimentary investigations. But, inadequacy of hysterosalpingography (HSG) in determining the state of tubal patency, emphasizes the need for laparoscopy. Laparoscopy provides both a panoramic view of the pelvic reproductive anatomy and a magnified view of pelvic organs and peritoneal surfaces. Keywords: Female infertility, Tubal patency, HSG, Laparoscopy

Dc arc emission analysis of rare earth metals and their oxides with sorption preconcentration of impurities

2018 ◽  
Vol 84 (11) ◽  
pp. 9-14
Author(s):  
E. S. Koshel ◽  
V. B. Baranovskaya ◽  
M. S. Doronina
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Analytical Signal ◽  
Graphite Powder ◽  
Atomic Emission ◽  
Standard Samples ◽  
Emission Analysis ◽  
Sorption Preconcentration ◽  
Sample Shape

The analytical capabilities of arc atomic emission determination of As, Bi, Sb, Cu, Te in rare earth metals (REM) and their oxides after preparatory group concentration using S,N-containing heterochain polymer sorbent are studied on a high-resolution spectrometer “Grand- Extra” (“WMC-Optoelectron-ics” company, Russia). Sorption kinetics and dependence of the degree of the impurity extraction on the solution acidity are analyzed to specify conditions of sorption concentration. To optimize the procedure of arc atomic emission determination of As, Bi, Sb, Cu, and Te various schemes of their sorption preconcentration and subsequent processing of the resulted concentrate with the addition of a collector at different stages of the sorption process have been considered. Graphite powder is used as a collector in analysis of rare earth oxides due to universality and relative simplicity of the emission spectrum. Conditions of analysis and parameters of the spectrometer that affect the analytical signal (mass and composition of the sample, shape and size of the electrodes, current intensity and generator operation mode, interelectrode spacing, wavelengths of the analytical lines) are chosen. The evaporation curves of the determinable impurities were studied and the exposure time of As, Bi, Sb, Cu, and Te in the resulted sorption concentrate was determined. Correctness of the obtained results was evaluated using standard samples of the composition and in comparisons between methods. The results of the study are used to develop a method of arc chemical-atomic emission analysis of yttrium, gadolinium, neodymium, europium, scandium and their oxides in a concentration range of n x (10-2 - 10-5) wt.%.

Simultaneous and Sensitive Determination of Amphetamine, Codeine and Morphine in Exhaled Breath Condensate, Using Capillary Electrophoresis Coupled with On-line and Off-line Enhancing Methods

2020 ◽  
Vol 16 (7) ◽  
pp. 872-879
Author(s):  
Samin Hamidi
Keyword(s):  
Drugs Of Abuse ◽  
Exhaled Breath Condensate ◽  
Direct Injection ◽  
Forensic Toxicology ◽  
Analytical Signal ◽  
Exhaled Breath ◽  
Concentration Method ◽  
Validation Parameters ◽  
Breath Condensate

Background: Abuse of drugs is associated with several medical, forensic, toxicology and social challenges. “Drugs of abuse” testing is therefore an important issue. Objective: We propose a simple CE-based method for the quantification of amphetamine, codeine and morphine after direct injection of Exhaled Breath Condensate (EBC) by the aid of simple stacking mode and an off-line pre-concentration method. Methods: Using graphene oxide adsorbents, amphetamine, codeine and morphine were extracted from EBC in order to eliminate the proteins and other interferences. In addition to off-line method, an online stacking mode was applied to improve the analytical signal obtained from the instrument. Results: The validation parameters were experimented on the developed method based on the FDA guideline over concentration ranges of 12.5-100, 30-500 and 10-1250 ng/mL associated with amphetamine, codeine and morphine, respectively. Small volumes (around 100 μL) of EBC were collected using a lab-made setup and successfully analyzed using the proposed method where precisions and accuracies (within day and between days) were in accordance with the guideline (recommended less than 15 % for biological samples). The recovery tests were used to evaluate the matrix effect and data (94 to 105 %) showed that the proposed method can be applied in different EBC matrix samplings of subjects. Conclusion: The proposed method is superior for simultaneous determination of amphetamine, codeine and morphine over chromatographic analyses because it is fast and consumes fewer chemicals, with no derivatization step.

scholarly journals An SPRi Biosensor for Determination of the Ovarian Cancer Marker HE4 in Human Plasma

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3567
Author(s):  
Beata Szymanska ◽  
Zenon Lukaszewski ◽  
Beata Zelazowska-Rutkowska ◽  
Kinga Hermanowicz-Szamatowicz ◽  
Ewa Gorodkiewicz
Keyword(s):  
Ovarian Cancer ◽  
Cancer Patients ◽  
Tumor Resection ◽  
Analytical Signal ◽  
Cancer Marker ◽  
Human Epididymis Protein 4 ◽  
Pearson Coefficient ◽  
Rabbit Polyclonal Antibody ◽  
Good Agreement

Human epididymis protein 4 (HE4) is an ovarian cancer marker. Various cut-off values of the marker in blood are recommended, depending on the method used for its determination. An alternative biosensor for HE4 determination in blood plasma has been developed. It consists of rabbit polyclonal antibody against HE4, covalently attached to a gold chip via cysteamine linker. The biosensor is used with the non-fluidic array SPRi technique. The linear range of the analytical signal response was found to be 2–120 pM, and the biosensor can be used for the determination of the HE4 marker in the plasma of both healthy subjects and ovarian cancer patients after suitable dilution with a PBS buffer. Precision (6–10%) and recovery (101.8–103.5%) were found to be acceptable, and the LOD was equal to 2 pM. The biosensor was validated by the parallel determination of a series of plasma samples from ovarian cancer patients using the Elecsys HE4 test and the developed biosensor, with a good agreement of the results (a Pearson coefficient of 0.989). An example of the diagnostic application of the developed biosensor is given—the influence of ovarian tumor resection on the level of HE4 in blood serum.

scholarly journals Recognition of Bimolecular Logic Operation Pattern Based on a Solid-State Nanopore

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 33
Author(s):  
Han Yan ◽  
Zhen Zhang ◽  
Ting Weng ◽  
Libo Zhu ◽  
Pang Zhang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Detection Method ◽  
Logic Gate ◽  
Detection Methods ◽  
Label Free ◽  
Recognition Method ◽  
Operation Pattern ◽  
Simple Detection ◽  
Dna Tetrahedron ◽  
Marker Molecule

Nanopores have a unique advantage for detecting biomolecules in a label-free fashion, such as DNA that can be synthesized into specific structures to perform computations. This method has been considered for the detection of diseased molecules. Here, we propose a novel marker molecule detection method based on DNA logic gate by deciphering a variable DNA tetrahedron structure using a nanopore. We designed two types of probes containing a tetrahedron and a single-strand DNA tail which paired with different parts of the target molecule. In the presence of the target, the two probes formed a double tetrahedron structure. As translocation of the single and the double tetrahedron structures under bias voltage produced different blockage signals, the events could be assigned into four different operations, i.e., (0, 0), (0, 1), (1, 0), (1, 1), according to the predefined structure by logic gate. The pattern signal produced by the AND operation is obviously different from the signal of the other three operations. This pattern recognition method has been differentiated from simple detection methods based on DNA self-assembly and nanopore technologies.

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