scholarly journals Immobilized Enzymes in Biosensor Applications

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 121 ◽  
Author(s):  
Hoang Hiep Nguyen ◽  
Sun Hyeok Lee ◽  
Ui Jin Lee ◽  
Cesar D. Fermin ◽  
Moonil Kim
Keyword(s):  
Point Of Care ◽  
Measurement Techniques ◽  
Diagnostic Testing ◽  
High Sensitivity ◽  
Immobilized Enzymes ◽  
Clinical Analysis ◽  
Safety Control ◽  
Wide Range ◽  
Piezoelectric Measurement ◽  
Innovative Techniques

Enzyme-based biosensing devices have been extensively developed over the last few decades, and have proven to be innovative techniques in the qualitative and quantitative analysis of a variety of target substrates over a wide range of applications. Distinct advantages that enzyme-based biosensors provide, such as high sensitivity and specificity, portability, cost-effectiveness, and the possibilities for miniaturization and point-of-care diagnostic testing make them more and more attractive for research focused on clinical analysis, food safety control, or disease monitoring purposes. Therefore, this review article investigates the operating principle of enzymatic biosensors utilizing electrochemical, optical, thermistor, and piezoelectric measurement techniques and their applications in the literature, as well as approaches in improving the use of enzymes for biosensors.

scholarly journals Programmable Paper-Based Microfluidic Devices for Biomarker Detections

Micromachines ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 516 ◽  
Author(s):  
Veasna Soum ◽  
Sooyong Park ◽  
Albertus Ivan Brilian ◽  
Oh-Sun Kwon ◽  
Kwanwoo Shin
Keyword(s):  
Point Of Care ◽  
High Sensitivity ◽  
Microfluidic Devices ◽  
Portable Devices ◽  
Biomarker Detection ◽  
Fluid Delivery ◽  
Wide Range ◽  
Paper Based Microfluidics ◽  
Digital Microfluidic ◽  
Detection Of Biomarkers

Recent advanced paper-based microfluidic devices provide an alternative technology for the detection of biomarkers by using affordable and portable devices for point-of-care testing (POCT). Programmable paper-based microfluidic devices enable a wide range of biomarker detection with high sensitivity and automation for single- and multi-step assays because they provide better control for manipulating fluid samples. In this review, we examine the advances in programmable microfluidics, i.e., paper-based continuous-flow microfluidic (p-CMF) devices and paper-based digital microfluidic (p-DMF) devices, for biomarker detection. First, we discuss the methods used to fabricate these two types of paper-based microfluidic devices and the strategies for programming fluid delivery and for droplet manipulation. Next, we discuss the use of these programmable paper-based devices for the single- and multi-step detection of biomarkers. Finally, we present the current limitations of paper-based microfluidics for biomarker detection and the outlook for their development.

Characterization of Anisotropic and Irregularly-Shaped Materials by High-Sensitive Thermal Conductivity Measurements

2007 ◽  
Vol 124-126 ◽  
pp. 1641-1644 ◽  
Author(s):  
M. Gustavsson ◽  
Hideaki Nagai ◽  
Takeshi Okutani
Keyword(s):  
Thermal Conductivity ◽  
Structural Changes ◽  
Bulk Material ◽  
Thermal Contact ◽  
Measurement Techniques ◽  
High Sensitivity ◽  
Conductivity Measurements ◽  
Destructive Testing ◽  
Analysis And Design ◽  
Wide Range

In modern thermal analysis and design involving thermal transport in solid components it is necessary to apply different modeling of the thermal heat flow in bulk material and across solid surface interfaces either in shape of a layer or a solid-solid interface. Similar differences occur when applying different measurement techniques. Some techniques have been developed specifically for the purpose of performing measurements of bulk properties by removing the influence from thermal contact resistance between the measurement probe and the sample material. Thermal conductivity measurements on metal and ceramic objects of various geometries such as thin bars, thin sheets as well as coatings or layers are here described when using the Transient Plane Source technique. A summary overview of the recent developments of this technique, including its ability to be applied in measurement situations covering a wide range of length and time scales, is also presented. Structural changes in anisotropy can be recorded with high sensitivity by comparative measurements. The technique may be applied in situations requiring non-destructive testing, e.g. samples of particular geometry used for mechanical or tensile testing.

Bioengineered Polymer/Composites as Advanced Biological Detection of Sorbitol: An Application in Healthcare Sector

2020 ◽  
Vol 20 (11) ◽  
pp. 963-981
Author(s):  
Ruma Rani ◽  
Geeta Singh ◽  
Kanisht Batra ◽  
Prasad Minakshi
Keyword(s):  
Point Of Care ◽  
Diagnostic Testing ◽  
High Sensitivity ◽  
Advanced Materials ◽  
Healthcare Sector ◽  
Biological Detection ◽  
Detection Techniques ◽  
Sensitivity And Selectivity ◽  
Healthcare Application ◽  
Higher Sensitivity

Bioengineered polymers and nanomaterials have emerged as promising and advanced materials for the fabrication and development of novel biosensors. Nanotechnology-enabled biosensor methods have high sensitivity, selectivity and more rapid detection of an analyte. Biosensor based methods are more rapid and simple with higher sensitivity and selectivity and can be developed for point-of-care diagnostic testing. Development of a simple, sensitive and rapid method for sorbitol detection is of considerable significance to efficient monitoring of diabetes-associated disorders like cataract, neuropathy, and nephropathy at initial stages. This issue encourages us to write a review that highlights recent advancements in the field of sorbitol detection as no such reports have been published till the date. The first section of this review will be dedicated to the conventional approaches or methods that had been playing a role in detection. The second part focused on the emerging field i.e. biosensors with optical, electrochemical, piezoelectric, etc. approaches for sorbitol detection and the importance of its detection in healthcare application. It is expected that this review will be very helpful for readers to know the different conventional and recent detection techniques for sorbitol at a glance.

scholarly journals Laboratory-based evaluation of a simplified point-of-care test intended to support treatment decisions in non-severe bovine clinical mastitis

2021 ◽  
pp. 1-6
Author(s):  
Francisco B. Malcata ◽  
P. Theo Pepler ◽  
Ruth N. Zadoks ◽  
Lorenzo Viora
Keyword(s):  
Predictive Value ◽  
Point Of Care ◽  
Diagnostic Testing ◽  
High Sensitivity ◽  
Treatment Decisions ◽  
Clinical Mastitis ◽  
Antimicrobial Treatment ◽  
Species Identity ◽  
Gram Positive ◽  
Slide Test

Abstract To limit the use of antimicrobials in dairy cattle, farmers are increasingly encouraged to adopt targeted treatment decisions based on knowledge of the pathogens causing clinical mastitis (CM), whereby treatment of non-severe CM is generally recommended for gram-positive mastitis but not for gram-negative or culture-negative mastitis. The objectives of this study were to conduct a laboratory-based evaluation of the performance of a simplified slide test as a tool to differentiate gram-positive CM from other cases of CM, and to compare its performance against a commercially available on-farm test that is commonly used in our area (VétoRapid). Test outcomes after 24–48 h incubation were compared to results from bacteriological culture and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS). Milk samples (n = 156) were obtained from cases of severe and non-severe CM on seven farms and collected by farm personnel. After removal of small numbers of contaminated samples and organisms with unknown species identity, the simplified slide test showed high sensitivity and accuracy (>80%), similar to the comparator test. For most outcomes of interest (culture positive, Escherichia coli, or gram-positive growth), the specificity of the slide test was higher than the specificity of the comparator test. When considering non-severe cases of CM only, and interpreting detection of gram-positive organisms as indicative of the need for antimicrobial treatment, the simplified test had higher specificity (77.4% v. 60.4%) and higher positive predictive value (79.7% v. 70.0%) than the comparator test and similar sensitivity (83.9% v. 87.5%). The proportion of sampled CM cases, contaminated samples and gram-positive mastitis cases – which affects the positive and negative predictive value, the economic value of diagnostic testing and its potential to reduce antimicrobial use – differed between farms. The simplicity and accuracy of the slide test could make it an attractive tool for farmers to target antimicrobial treatment of non-severe clinical mastitis.

scholarly journals Point-of-care ultrasound in primary care: a systematic review of generalist performed point-of-care ultrasound in unselected populations

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Bjarte Sorensen ◽  
Steinar Hunskaar
Keyword(s):  
Systematic Review ◽  
Emergency Medicine ◽  
General Practitioners ◽  
Clinical Studies ◽  
Point Of Care ◽  
High Sensitivity ◽  
High Specificity ◽  
Point Of Care Ultrasound ◽  
Organ Systems ◽  
Wide Range

Abstract Background Both the interest and actual extent of use of point-of-care ultrasound, PoCUS, among general practitioners or family physicians are increasing and training is also increasingly implemented in residency programs. However, the amount of research within the field is still rather limited compared to what is seen within other specialties in which it has become more established, such as in the specialty of emergency medicine. An assumption is made that what is relevant for emergency medicine physicians and their populations is also relevant to the general practitioner, as both groups are generalists working in unselected populations. This systematic review aims to examine the extent of use and to identify clinical studies on the use of PoCUS by either general practitioners or emergency physicians on indications that are relevant for the former, both in their daily practice and in out-of-hours services. Methods Systematic searches were done in PubMed/MEDLINE using terms related to general practice, emergency medicine, and ultrasound. Results On the extent of use, we identified 19 articles, as well as 26 meta-analyses and 168 primary studies on the clinical use of PoCUS. We found variable, but generally low, use among general practitioners, while it seems to be thoroughly established in emergency medicine in North America, and increasingly also in the rest of the world. In terms of clinical studies, most were on diagnostic accuracy, and most organ systems were studied; the heart, lungs/thorax, vessels, abdominal and pelvic organs, obstetric ultrasound, the eye, soft tissue, and the musculoskeletal system. The studies found in general either high sensitivity or high specificity for the particular test studied, and in some cases high total accuracy and superiority to other established diagnostic imaging modalities. PoCUS also showed faster time to diagnosis and change in management in some studies. Conclusion Our review shows that generalists can, given a certain level of pre-test probability, safely use PoCUS in a wide range of clinical settings to aid diagnosis and better the care of their patients.

scholarly journals Analytical Performances of the Point-of-Care BIOSYNEX COVID-19 Ag BSS for the Detection of SARS‐CoV‐2 Nucleocapsid Protein in Nasopharyngeal Swabs: A Prospective Field Evaluation During the COVID-19 Third Wave in France

2021 ◽  
Author(s):  
Fréderic Fitoussi ◽  
Serge Tonen-Wolyec ◽  
Natalio Awaida ◽  
Raphael Dupont ◽  
Laurent Belec
Keyword(s):  
Nucleocapsid Protein ◽  
Point Of Care ◽  
Diagnostic Testing ◽  
High Sensitivity ◽  
High Specificity ◽  
Field Evaluation ◽  
N Gene ◽  
Third Wave ◽  
Perfect Agreement ◽  
Viral Excretion

Abstract Background: Evaluating the accuracy and reliability of rapid diagnostic testing kits is crucial for surveillance and diagnosis of SARS-CoV-2 infections in general population. The aim of the study was to assess the analytical performances of the antigen-rapid diagnosis test (Ag-RDT) BIOSYNEX COVID-19 Ag BSS (Biosynex Swiss SA, Freiburg, Switzerland), targeting the SARS-CoV-2 N nucleocapsid protein, for the diagnosis of COVID-19, by reference to real-time RT-PCR (rtRT-PCR).Methods: A total 967 adults living in Paris region were prospectively included during the third wave of the COVID-19 epidemic in France. Paired nasopharyngeal flocked swabs were collected at the same timepoint from persons aged ≥18 years receiving testing for SARS-CoV-2, at two private laboratories.Results: Overall, the Ag-RDT showed high sensitivity, specificity, PPV and NPV of 81.8%, 99.6%, 96.6% and 97.5%, respectively, as well as high or almost perfect agreement (97.0%), reliability assessed by Cohen’s κ coefficient (0.87), and accuracy assessed by Youden’s J index (81.6%) to detect SARS-CoV-2. The analytical performances of the Ag-RDT remained high in the event of significant viral excretion (i.e., N gene Ct values ≤ 33 by reference rtRT-PCR), while the sensitivity of the Ag-RDT dropped to 55.2% with low or very low viral shedding (Ct> 33).Conclusions: The Ag-RDT BIOSYNEX COVID-19 Ag BSS showed high specificity and sufficient sensitivity for the detection of SARS-CoV-2. This test is a promising potential easy diagnostic tool, especially in situations of symptomatic COVID-19 and/or proven contagiousness.

scholarly journals Development and Validation of the Elecsys Anti-SARS-CoV-2 Immunoassay as a Highly Specific Tool for Determining Past Exposure to SARS-CoV-2

2020 ◽  
Vol 58 (10) ◽  
Author(s):  
Peter Muench ◽  
Simon Jochum ◽  
Verena Wenderoth ◽  
Beatus Ofenloch-Haehnle ◽  
Michael Hombach ◽  
...  
Keyword(s):  
Blood Donors ◽  
Diagnostic Testing ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Point Estimates ◽  
Wide Range ◽  
Vesicular Stomatitis ◽  
Sensitivity Specificity ◽  
Development And Validation ◽  
Roche Diagnostics

ABSTRACT The Elecsys Anti-SARS-CoV-2 immunoassay (Roche Diagnostics) was developed to provide accurate, reliable detection of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluated sensitivity, specificity, cross-reactivity, and agreement with a vesicular stomatitis virus-based pseudoneutralization assay for the Elecsys Anti-SARS-CoV-2 immunoassay. Sensitivity and agreement between Elecsys Anti-SARS-CoV-2 immunoassay and pseudoneutralization assay measurements were evaluated using samples from patients with PCR-confirmed SARS-CoV-2 infection, a majority of whom were hospitalized. Specificity was evaluated using samples from routine diagnostic testing/blood donors collected before December 2019 and thus deemed negative for SARS-CoV-2-specific antibodies. Cross-reactivity was evaluated using samples containing a wide range of potentially cross-reacting analytes, purchased from commercial vendors. For sensitivity and specificity, point estimates and 95% confidence intervals (CIs) were calculated. Agreement between the Elecsys Anti-SARS-CoV-2 immunoassay and the pseudoneutralization assay was calculated. The sensitivity of the Elecsys Anti-SARS-CoV-2 immunoassay in patients with prior PCR-confirmed SARS-CoV-2 infection was 99.5% (95% CI, 97.0 to 100.0%) at ≥14 days post-PCR confirmation. Overall specificity (n = 10,453) was 99.80% (95% CI, 99.69 to 99.88%). Only 4/792 samples containing potential cross-reacting analytes were reactive with the Elecsys Anti-SARS-CoV-2 immunoassay, resulting in an overall specificity in this cohort of 99.5% (95% CI, 98.6 to 99.9%). Positive, negative, and overall agreement (n = 46) between the Elecsys Anti-SARS-CoV-2 immunoassay and the pseudoneutralization assay were 86.4% (95% CI, 73.3 to 93.6%), 100% (95% CI, 34.2 to 100%), and 87.0% (95% CI, 74.3 to 93.9%), respectively. The Elecsys Anti-SARS-CoV-2 immunoassay demonstrated high sensitivity (99.5% at ≥14 days post-PCR confirmation) and specificity (99.80%), supporting its use as a tool for identification of past SARS-CoV-2 infection, including use in populations with low disease prevalence.

scholarly journals Hydroxymethylbilane synthase (HMBS) gene-based endogenous internal control for avian species

AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yaoyao Wang ◽  
Jilei Zhang ◽  
Kelly Patrick ◽  
Min Li ◽  
Jiansen Gong ◽  
...  
Keyword(s):  
Internal Control ◽  
Diagnostic Testing ◽  
High Sensitivity ◽  
Avian Species ◽  
Gene Copy ◽  
Molecular Diagnostic ◽  
Diagnostic Tools ◽  
Dna And Rna ◽  
Wide Range ◽  
And Storage

Abstract With PCR becoming one of the most important and widely-used diagnostic tools for infectious diseases of poultry, an urgent need has developed for an endogenous internal control (EIC) that monitors the quality and quantity of poultry DNA in test samples. In this study we developed a SYBR-qPCR to target the poultry homolog of the hydroxymethylbilane synthase (HMBS) gene as an EIC for avian species. The avian HMBS-based qPCR was very sensitive, detecting one HMBS gene copy in a 20 µL reaction, and is highly specific for avian species. It amplified DNA from 11 organs and tissues of chickens showing it can be used as an EIC on a large variety of samples. The application of the established EIC on clinically and experimentally infected samples demonstrated that false negativity and result variations could result from samples being collected using different operators, techniques, preservatives, and storage times. The high sensitivity and specificity of the avian HMBS-based qPCR, its ability to quantify DNAs extracted from a wide range of tissues and poultry species along with its usefulness in reducing false negativity in PCR results associated with inadequate sampling and storage degradation makes it an ideal EIC for poultry DNA and RNA PCR diagnostics. The study also highlights the importance of appropriate sampling and storage of samples in ensuring accuracy of molecular diagnostic testing.

Novel High Sensitivity Tuberculosis Point-of-Care Test for People Living with HIV

2018 ◽  
Author(s):  
Tobias Broger ◽  
Bianca Sossen ◽  
Elloise du Toit ◽  
Andrew D. Kerkhoff ◽  
Charlotte Schutz ◽  
...  
Keyword(s):  
Point Of Care ◽  
High Sensitivity ◽  
People Living With Hiv ◽  
Point Of Care Test ◽  
Living With Hiv

Trends in Diagnosis for Active Tuberculosis Using Nanomaterials

2019 ◽  
Vol 26 (11) ◽  
pp. 1946-1959 ◽  
Author(s):  
Le Minh Tu Phan ◽  
Lemma Teshome Tufa ◽  
Hwa-Jung Kim ◽  
Jaebeom Lee ◽  
Tae Jung Park
Keyword(s):  
Sensitivity And Specificity ◽  
High Efficiency ◽  
Point Of Care ◽  
High Sensitivity ◽  
Signs And Symptoms ◽  
Diagnostic Methods ◽  
Advantages And Disadvantages ◽  
Treatment And Prevention ◽  
Clinical Tools ◽  
Diagnostic Applications

Background:Tuberculosis (TB), one of the leading causes of death worldwide, is difficult to diagnose based only on signs and symptoms. Methods for TB detection are continuously being researched to design novel effective clinical tools for the diagnosis of TB.Objective:This article reviews the methods to diagnose TB at the latent and active stages and to recognize prospective TB diagnostic methods based on nanomaterials.Methods:The current methods for TB diagnosis were reviewed by evaluating their advantages and disadvantages. Furthermore, the trends in TB detection using nanomaterials were discussed regarding their performance capacity for clinical diagnostic applications.Results:Current methods such as microscopy, culture, and tuberculin skin test are still being employed to diagnose TB, however, a highly sensitive point of care tool without false results is still needed. The utilization of nanomaterials to detect the specific TB biomarkers with high sensitivity and specificity can provide a possible strategy to rapidly diagnose TB. Although it is challenging for nanodiagnostic platforms to be assessed in clinical trials, active TB diagnosis using nanomaterials is highly expected to achieve clinical significance for regular application. In addition, aspects and future directions in developing the high-efficiency tools to diagnose active TB using advanced nanomaterials are expounded.Conclusion:This review suggests that nanomaterials have high potential as rapid, costeffective tools to enhance the diagnostic sensitivity and specificity for the accurate diagnosis, treatment, and prevention of TB. Hence, portable nanobiosensors can be alternative effective tests to be exploited globally after clinical trial execution.

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