A novel approach to design electrochemical aptamer-based biosensor for ultrasensitive detecting of zearalenone as a prevalent estrogenic mycotoxin

2021 ◽  
Vol 28 ◽  
Author(s):  
Shokoufeh Hassani ◽  
Armin Salek Maghsoudi ◽  
Milad Rezaei Akmal ◽  
Shahram Shoeibi ◽  
Fatemeh Ghadipasha ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Electrochemical Impedance ◽  
Fusarium Species ◽  
High Sensitivity ◽  
High Specificity ◽  
Cost Effective ◽  
Differential Pulse ◽  
Electrode Position ◽  
Novel Approach ◽  
Modified Surface

Background: Zearalenone is a well-known estrogenic mycotoxin produced by Fusarium species, a serious threat to the agricultural and food industries worldwide. Zearalenone, with its known metabolites, are biomarkers of exposure to certain fungi, primarily through food. It has considerable toxic effects on biological systems due to its carcinogenicity, mutagenicity, renal toxicity, teratogenicity, and immunotoxicity. Introduction: This study aims to design a simple, quick, precise, and cost-effective method on a biosensor platform to evaluate the low levels of this toxin in foodstuffs and agricultural products. Methods: An aptamer-based electrochemical biosensor was introduced that utilizes screen-printed gold electrodes instead of conventional electrodes. The electrode position process was employed to develop a gold nanoparticle-modified surface to enhance the electroactive surface area. Thiolated aptamers were immobilized on the surface of gold nanoparticles, and subsequently, the blocker and analyte were added to the modified surface. In the presence of a redox probe, electrochemical characterization of differential pulse voltammetry, cyclic voltammetry, and electrochemical impedance spectroscopy were used to investigate the various stages of aptasensor fabrication. Results: The proposed aptasensor for zearalenone concentration had a wide linear dynamic range covering the 0.5 pg/mL to 100 ng/mL with a 0.14 pg/mL detection limit. Moreover, this aptasensor had high specificity so that a non-specific analyte cannot negatively affect the selectivity of the aptasensor. Conclusion: Overall, due to its simple design, high sensitivity, and fast performance, this aptasensor showed a high potential for assessing zearalenone in real samples, providing a clear perspective for designing a portable and cost-effective device.

Preparation of yolk–shell structured Ag@Cu particles and their application in high performance electrochemical sensing of p-aminobenzoic acid

2019 ◽  
Vol 97 (2) ◽  
pp. 140-146
Author(s):  
Tian Gan ◽  
Zhikai Wang ◽  
Mengru Chen ◽  
Wanqiu Fu ◽  
Haibo Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Performance ◽  
Electrochemical Impedance ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Electrochemical Sensing ◽  
High Catalytic Activity ◽  
Aminobenzoic Acid ◽  
Transmission Electron

In this work, the Ag@Cu particles with yolk–shell nanostructure was prepared by facile solvothermal method, which was modified on glassy carbon electrode (GCE) to fabricate electrochemical sensor for the convenient and fast determination of p-aminobenzoic acid (PABA). The surface morphology and electrochemical properties of the as-prepared Ag@Cu nanocomposite modified electrode were characterized by scanning electron microscopy, transmission electron microscopy, chronocoulometry, and electrochemical impedance spectroscopy. Further, the electrochemical sensing of PABA was performed on the Ag@Cu/GCE using cyclic voltammetry and differential pulse voltammetry techniques, showing high catalytic activity. Under the optimal conditions, the sensor exhibited a wide linear range, high sensitivity, and low detection limit of 0.315 μmol/L for PABA. The developed sensor was also successfully applied for PABA detection in anesthetic and cosmetics with satisfactory results.

An Amperometric Immunosensor for α-Fetoprotein Based on Antibody Coated Nano ZrO2-Au-Poly Lysine Composite Membrane Modified Electrode

2011 ◽  
Vol 343-344 ◽  
pp. 490-496 ◽  
Author(s):  
Yuan Zhao Wu ◽  
Fu Tao Hu ◽  
Ning Gan ◽  
Jian Guo Hou ◽  
Tian Hua Li ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Composite Membrane ◽  
Electrochemical Impedance ◽  
Signal To Noise Ratio ◽  
Cost Effective ◽  
Differential Pulse ◽  
Phenoxyacetic Acid ◽  
Serum Samples ◽  
Amperometric Immunosensor ◽  
Sensitivity And Selectivity

One novel amperometric immunosensor for α-fetop- rotein was fabricated which was modified by antibody immobilized on nano ZrO2-Au-polyLysine composite membrane. Firstly, the deoxyribonucleic acid – phenoxyacetic acid isoniazid- Schiff base Co(II) complex (DNA-CoL) mixture film was casted on surface of multi carbon nanotubes(MWCNTs) modified glassy carbon electrode(GCE/CNTs/DNA-CoL). Then the composite nanoparticles (ZrO2-Au-pLL) was employed to immobilize the antibody of α-fetoprotein(AFP) to produce the probes(ZrO2-Au-pLL-anti AFP) for AFP. Finally the probes were modified on GCE/CNTs/DNA-CoL through the specific connection between DNA and ZrO2 to form a novel nanocomposite membrane immunosensor for AFP(GCE/CNTs/ DNA-CoL/ZrO2-Au–pLL-anti AFP). The function of immunosensor was investigated by scanning electron microscopy (SEM), cyclic voltammetry(CV), differential pulse voltammety (DPV) and electrochemical impedance spectroscopy experiment (EIS). The results indicated that combining the advantages of the MWNTs-DNA material and ZrO2-Au-pLL-anti AFP nano probes, the immunosensor with excellent sensitivity and selectivity to AFP was prepared successfully. The modified electrode was sensitive to AFP with a linear relationship between 0.05 and 10 ng · mL−1 and a correl- ation coefficient of 0.9905. The detection limit at a signal to noise ratio of 3 was 0.01 ng·mL−1 under the optimal conditions. The described immunosensor preparation and immunoassay methods offer promise for simple and cost-effective analysis of AFP in serum samples.

scholarly journals Screen-Printed Sensor Based on Potentiometric Transduction for Free Bilirubin Detection as a Biomarker for Hyperbilirubinemia Diagnosis

Chemosensors ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 86 ◽  
Author(s):  
Ayman H. Kamel ◽  
Abd El-Galil E. Amr ◽  
Hoda R. Galal ◽  
Mohamed A. Al-Omar ◽  
Abdulrahman A. Almehizia
Keyword(s):  
Electrochemical Impedance ◽  
Biological Fluids ◽  
Ion Association ◽  
High Specificity ◽  
Cost Effective ◽  
Pvc Membrane ◽  
Phosphate Solution ◽  
High Potential Stability ◽  
Potential Stability ◽  
Screen Printed

Novel reliable and cost-effective potentiometric screen-printed sensors for free bilirubin (BR) detection were presented. The sensors were fabricated using ordered mesoporous carbon (OMC) as an ion-to-electron transducer. The ion-association complex [Ni(bphen)3]2+[BR]2− was utilized as a sensory recognition material in the plasticized Polyvinyl Chloride (PVC) membrane. The membrane was drop-casted on the OMC layer, which is attached on a carbon conductor (2-mm diameter). In a 50 mM phosphate solution of pH 8.5, the electrodes offered a Nernstian slope of −26.8 ± 1.1 (r2 = 0.9997) mV/decade with a range of linearity 1.0 × 10−6–1 × 10−2 M towards free bilirubin with a detection limit 8.8 × 10−7 M (0.52 µg/mL). The presented sensors offered good features in terms of reliability, ease of design, high potential stability, high specificity and good accuracy and precision. Chronopotentiometric and electrochemical impedance spectrometric measurements were used for short-term potential stability and interfacial capacitance calculations. The sensors were used for the determination of free bilirubin in biological fluids. The data obtained are fairly well consistent with those obtained by the reference spectophotometric method. Based on the interaction of free BR with albumin (1:1), the sensors were also utilized for the assessment of albumin in human serum.

Rapid, targeted and culture-free viral infectivity assay in drop-based microfluidics

Lab on a Chip ◽  
2015 ◽  
Vol 15 (19) ◽  
pp. 3934-3940 ◽  
Author(s):  
Ye Tao ◽  
Assaf Rotem ◽  
Huidan Zhang ◽  
Connie B. Chang ◽  
Anindita Basu ◽  
...  
Keyword(s):  
High Throughput ◽  
Dynamic Range ◽  
High Sensitivity ◽  
Cost Effective ◽  
Serial Dilution ◽  
Viral Infectivity ◽  
Large Dynamic Range ◽  
Infectivity Assay ◽  
Dilution Experiments

We developed a rapid, targeted and culture-free infectivity assay using high-throughput drop-based microfluidics. The high sensitivity and large dynamic range of our cost effective assay alleviates the need for serial dilution experiments.

scholarly journals An electrochemical DNA biosensor for trace amounts of mercury ion quantification

2016 ◽  
Vol 14 (5) ◽  
pp. 808-815 ◽  
Author(s):  
Ferdaous Maâtouk ◽  
Mouna Maâtouk ◽  
Karima Bekir ◽  
Houcine Barhoumi ◽  
Abderrazak Maaref ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Specific Interaction ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Mercury Ion ◽  
Dna Biosensor ◽  
Electrochemical Dna Biosensor ◽  
Dna Oligonucleotides ◽  
Wastewater Samples ◽  
Eis Measurements

In this work we report the development of an electrochemical DNA biosensor with high sensitivity for mercury ion detection. A new matrix based on gold nanoparticles (AuNPs)-glutathione (GSH)/cysteine was investigated. The interaction between DNA oligonucleotides and Hg2+ ions followed by the formation of Thymine–Hg2+–Thymine (T–Hg2+–T) structures was quantified using different electrochemical methods. It has been shown that the electrochemical impedance spectroscopy (EIS) measurements and the differential pulse voltammetry (DPV) confirmed the specific interaction between the oligonucleotide receptor layer and the Hg2+ ions. Besides, the developed sensor exhibited high sensitivity towards mercury among some examined metal ions such as Pb2+, Cu2+ and Cd2+. As a result, a high electrochemical response and low detection limit of 50 pM were estimated in the case of Hg2+ ions. The developed DNA biosensor was applied successfully to the determination of Hg2+ions in wastewater samples.

scholarly journals Prediction of Preterm Birth: Maternal Characteristics, Ultrasound Markers, and Biomarkers: An Updated Overview

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Zeynep Asli Oskovi Kaplan ◽  
A. Seval Ozgu-Erdinc
Keyword(s):  
Preterm Birth ◽  
Screening Method ◽  
High Sensitivity ◽  
High Specificity ◽  
Cost Effective ◽  
Strain Ratio ◽  
Cervical Length ◽  
Health Condition ◽  
Fetal Fibronectin ◽  
Maternal Characteristics

There is not a single or combined screening method for preterm birth with high sensitivity which will truly identify the women at risk for preterm birth while also with high specificity to prevent unnecessary interventions and high treatment costs. Measurement of cervical length is the most cost-effective method that is used in clinical practice. Bedside tests have also been developed for detecting markers like fetal fibronectin, insulin-like growth factor binding protein-1 (IGFBP-1), interleukin-6, and placental alpha-macroglobulin-1. Taking the maternal history, health condition, and sociodemographical factors into consideration is recommended. Ultrasound markers apart from cervical length measurements as uterocervical angle and placental strain ratio are studied. Investigations on metabolomics, proteomics, and microRNA profiling have brought a new aspect on this subject. Maybe in the future, with clear identification of women at true risk for preterm birth, development of more effective preventive strategies will not be unfeasible.

scholarly journals Molecular markers in the diagnosis of thyroid nodules

2013 ◽  
Vol 57 (2) ◽  
pp. 89-97 ◽  
Author(s):  
Laura S. Ward ◽  
Richard T. Kloos
Keyword(s):  
Predictive Value ◽  
High Sensitivity ◽  
High Specificity ◽  
Cost Effective ◽  
Needle Aspiration ◽  
Molecular Diagnostic ◽  
Risk Of Malignancy ◽  
Benign Nodules ◽  
Low Sensitivity ◽  
Rule Out

An indeterminate thyroid nodule cytology result occurs about every sixth fine-needle aspiration. These indeterminate nodules harbor a 24% risk of malignancy (ROM); too high to ignore, but driving surgery where most nodules are benign. Molecular diagnostics have emerged to ideally avoid surgery when appropriate, and to trigger the correct therapeutic surgery when indicated, as opposed to an incomplete diagnostic surgery. No current molecular test offers both high sensitivity and high specificity. A molecular diagnostic test with high sensitivity (e.g. Afirma Gene Expression Classifier sensitivity 90%) offers a high Negative Predictive Value when the ROM is relatively low, such as < 30%. Only such tests can "rule-out" cancer. In this setting, a molecularly benign result suggests the same ROM as that of operated cytologically benign nodules (~6%). Thus, clinical observation can replace diagnostic surgery; increasing quality of life and decreasing medical costs. However, its low specificity cannot "rule-in" cancer as a suspicious result has a Positive Predictive Value (PPV) of ~40%, perhaps too low to routinely reflex to definitive cancer surgery. Conversely, high specificity tests (BRAF, RAS, PPAR/PAX-8, RET/PTC, PTEN) offer high PPV results, and only these tests can "rule-in" cancer. Here a positive molecular result warrants definitive therapeutic surgery. However, their low sensitivity cannot "rule-out" cancer and a negative molecular result cannot dissuade diagnostic surgery; limiting their cost-effectiveness. Whether or not there is a useful and cost-effective role to sequentially combine these approaches, or to modify existing approaches, is under investigation.

Decision Analysis of Auditory Brainstem Responses and Rotational Vestibular Tests in Acoustic Tumor Diagnosis

1987 ◽  
Vol 96 (1) ◽  
pp. 22-29 ◽  
Author(s):  
Charles A. Mangham
Keyword(s):  
Decision Analysis ◽  
High Sensitivity ◽  
High Specificity ◽  
Cost Effective ◽  
Auditory Brainstem ◽  
Tumor Diagnosis ◽  
Auditory Brainstem Responses ◽  
Test Protocol ◽  
Brainstem Response ◽  
Acoustic Tumor

This study addresses the problem of the escalation of the costs of medical care which make diagnosis of acoustic tumor expensive. Specifically, we examined the hypothesis that a test protocol of the auditory brainstem response (ABR) in parallel with sinusoidal harmonic acceleration (SHA) is more cost-effective in identification of the risk of tumor than ABR alone. The subjects were 74 patients with acoustic tumors and 78 controls. ABR and SHA data from these subjects were submitted to decision analysis. ABR was more cost-effective than the protocol of ABR in parallel with SHA. Using these data, we outlined a “decision tree” for acoustic tumor diagnosis that fit the goals of high sensitivity when earlier probability of tumor was high, and high specificity when earlier probability of tumor was low.

scholarly journals Evaluation of RNA extraction free method for detection of SARS-COV-2 in salivary samples for mass screening for COVID-19

2021 ◽  
Author(s):  
Sally A. Mahmoud ◽  
Esra Ibrahim ◽  
Subhashini Ganesan ◽  
Bhagyashree Thakre ◽  
Juliet G Teddy ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Gold Standard ◽  
Rna Extraction ◽  
High Sensitivity ◽  
High Specificity ◽  
Cost Effective ◽  
Kappa Coefficient ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Good Percentage

AbstractIn this current COVID - 19 pandemic, there is a dire need for cost effective and less time-consuming alternatives for SARS-COV-2 testing. The RNA extraction free method for detecting SARS-COV-2 in saliva is a promising option, this study found that it has high sensitivity (85.34%), specificity (95.04%) and was comparable to the gold standard nasopharyngeal swab. The method showed good percentage of agreement (kappa coefficient) 0.797 between salivary and NPS samples. However, there are variations in the sensitivity and specificity based on the RT-PCR kit used. The Thermo Fischer-Applied biosystems showed high sensitivity, PPV and NPV but also showed higher percentage of invalid reports. Whereas the BGI kit showed high specificity, better agreement (kappa coefficient) between the results of saliva and NPS samples and higher correlation between the Ct values of saliva and NPS samples. Thus, the RNA extraction free method for salivary sample serves as an effective alternative for SARS-CoV 2-testing.

scholarly journals Comparative sensitivity of the test with tuberculosis recombinant allergen, containing ESAT6-CFP10 protein, and Mantoux test with 2 TU PPD-L in newly diagnosed tuberculosis children and adolescents in Moscow

2018 ◽  
Author(s):  
Liudmila Slogotskaya ◽  
Elena Bogorodskaya ◽  
Diana Ivanova ◽  
Tatiana Sevostyanova
Keyword(s):  
Children And Adolescents ◽  
Mass Screening ◽  
Skin Testing ◽  
High Sensitivity ◽  
High Specificity ◽  
Cost Effective ◽  
Mantoux Test ◽  
Recombinant Allergen ◽  
Newly Diagnosed ◽  
Comparative Sensitivity

AbstractBackground. A group of Russian scientists has developed Diaskintest, which comprises Mycobacterium tuberculosis-specific recombinant proteins CFP10-ESAT6, for skin testing (0.2 µg/0.1 ml).Study purpose: to evaluate the comparative sensitivity of TST with 2 TU PPD-L and a skin test with tuberculous recombinant allergen (Diaskintest) containing the ESAT6-CFP10 protein in children and adolescents with newly diagnosed respiratory tuberculosis during mass screening in the primary medical service in Moscow, 2013–2016.Materials and methods. The trial was a comprehensive retrospective group study of children and adolescents diagnosed in Moscow with respiratory tuberculosis in 2013–2016, aged 0 to 17 years inclusive. From 441 patients selected for analysis 408 patients had both tests (TST with 2 TU PPD-L and Diaskintest) performed, in 193 patients both tests were given simultaneously, of them 162 patients were BCG-vaccinated.Results. Comparative results of both tests in 408 patients with tuberculosis: at cut-off 5 mm, both tests has similar sensitivity: Diaskintest 98.3 % (95 % CI 97.0–99.6 %), TST 98.0 % (95 % CI 96.7–99.4 %), at cut-off 10 mm, the sensitivity decreases for both tests: Diaskintest 90.0 % (95 % CI 87.0–93.0 %), TST 88.7 % (95 % CI 85.6–91.9 %), but at cut-off 15 mm, the decrease in sensitivity is statistically significant: for Diaskintest 61.5 % (95 % CI 56.7–66.3 %), and for TST 46.3 % (95 % CI 41.4–51.3 %), p <0.0001.The results of simultaneous setting of tests on different hands in 193 people (including 162 BCG-vaccinated), do not differ from the results for 408 people.The correlation between the results of Diaskintest and TST was significant in all groups.Conclusion. In children and adolescents with respiratory tuberculosis, Diaskintest of 0.2 µg/ml and the Mantoux test with 2 TU PPD-L have high sensitivity (98%) at a cut-off of 5 mm; however, at cut-off 15 mm sensitivity is significantly reduced, and the decrease is more pronounced in the Mantoux test. The advantage of Diaskintest is that, unlike the Mantoux test, it has high specificity under the conditions of mass BCG vaccination. The test is cost-effective, simple to carry out, and can be used in mass screening.

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