scholarly journals Inkjet-printed point-of-care immunoassay on a nanoscale polymer brush enables subpicomolar detection of analytes in blood

2017 ◽  
Vol 114 (34) ◽  
pp. E7054-E7062 ◽  
Author(s):  
Daniel Y. Joh ◽  
Angus M. Hucknall ◽  
Qingshan Wei ◽  
Kelly A. Mason ◽  
Margaret L. Lund ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
High Performance ◽  
Point Of Care ◽  
Polymer Brush ◽  
Quantitative Detection ◽  
Figures Of Merit ◽  
Point Of Care Test ◽  
Resource Limited ◽  
Multiple Analytes ◽  
On Chip

The ELISA is the mainstay for sensitive and quantitative detection of protein analytes. Despite its utility, ELISA is time-consuming, resource-intensive, and infrastructure-dependent, limiting its availability in resource-limited regions. Here, we describe a self-contained immunoassay platform (the “D4 assay”) that converts the sandwich immunoassay into a point-of-care test (POCT). The D4 assay is fabricated by inkjet printing assay reagents as microarrays on nanoscale polymer brushes on glass chips, so that all reagents are “on-chip,” and these chips show durable storage stability without cold storage. The D4 assay can interrogate multiple analytes from a drop of blood, is compatible with a smartphone detector, and displays analytical figures of merit that are comparable to standard laboratory-based ELISA in whole blood. These attributes of the D4 POCT have the potential to democratize access to high-performance immunoassays in resource-limited settings without sacrificing their performance.

scholarly journals A haemagglutination test for rapid detection of antibodies to SARS-CoV-2

2020 ◽  
Author(s):  
Alain Townsend ◽  
Pramila Rijal ◽  
Julie Xiao ◽  
Tiong Kit Tan ◽  
Kuan-Ying A Huang ◽  
...  
Keyword(s):  
High Performance ◽  
Point Of Care ◽  
Low Cost ◽  
Glycophorin A ◽  
Red Cell ◽  
Special Equipment ◽  
Cell Agglutination ◽  
Haemagglutination Test ◽  
Point Of Care Test ◽  
Laboratory Facilities

ABSTRACTSerological detection of antibodies to SARS-CoV-2 is essential for establishing rates of seroconversion in populations, detection of seroconversion after vaccination, and for seeking evidence for a level of antibody that may be protective against COVID-19 disease. Several high-performance commercial tests have been described, but these require centralised laboratory facilities that are comparatively expensive, and therefore not available universally. Red cell agglutination tests have a long history in blood typing, and general serology through linkage of reporter molecules to the red cell surface. They do not require special equipment, are read by eye, have short development times, low cost and can be applied as a Point of Care Test (POCT). We describe a red cell agglutination test for the detection of antibodies to the SARS-CoV-2 receptor binding domain (RBD). We show that the Haemagglutination Test (“HAT”) has a sensitivity of 90% and specificity of 99% for detection of antibodies after a PCR diagnosed infection. The HAT can be titrated, detects rising titres in the first five days of hospital admission, correlates well with a commercial test that detects antibodies to the RBD, and can be applied as a point of care test. The developing reagent is composed of a previously described nanobody to a conserved glycophorin A epitope on red cells, linked to the RBD from SARS-CoV-2. It can be lyophilised for ease of shipping. We have scaled up production of this reagent to one gram, which is sufficient for ten million tests, at a cost of ∼0.27 UK pence per test well. Aliquots of this reagent are ready to be supplied to qualified groups anywhere in the world that need to detect antibodies to SARS-CoV-2, but do not have the facilities for high throughput commercial tests.

Multicenter Evaluation of HemoTypeSC as a Point-of-Care Sickle Cell Disease Rapid Diagnostic Test for Newborns and Adults Across India

2019 ◽  
Vol 153 (1) ◽  
pp. 82-87 ◽  
Author(s):  
Malay B Mukherjee ◽  
Roshan B Colah ◽  
Pallavi R Mehta ◽  
Nikhil Shinde ◽  
Dipty Jain ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Newborn Screening ◽  
Sickle Cell ◽  
High Performance ◽  
Screening Program ◽  
Point Of Care ◽  
Genetic Disorder ◽  
Cell Disease ◽  
Point Of Care Test ◽  
Tribal Areas

Abstract Objectives Sickle cell anemia is the commonest genetic disorder in India, and the frequency of the sickle cell gene is very high in the remote tribal areas where facilities are generally limited. Therefore, a rapid and affordable point-of-care test for sickle cell disease is needed. Methods The diagnostic accuracy of HemoTypeSC was evaluated against automated high-performance liquid chromatography (HPLC) as the gold standard for its efficacy in a newborn screening program. Results A total of 1,559 individuals (980 newborns and 579 adults) from four participating centers were analyzed by both methods. HemoTypeSC correctly identified 209 of 211 total hemoglobin (Hb) SS cases, for a 99.1%/99.9% total HbSS sensitivity/specificity. Overall, HemoTypeSC exhibited sensitivity and specificity of 98.1% and 99.1% for all possible phenotypes (HbAA, HbAS, and HbSS) detected. HPLC is relatively expensive and not available in most laboratories in remote tribal areas. Conclusions We conclude that the rapid, point-of-care testing device HemoTypeSC test is suitable for population and newborn screening for the HbS phenotype.

scholarly journals TUBERCULOUS PERICARDITIS AND PLEURITIS;

2017 ◽  
Vol 24 (05) ◽  
pp. 656-664
Author(s):  
Hamid Mahmood ◽  
Talmeez Zaib ◽  
Zafar Hayat Maken ◽  
Ammara Waqar ◽  
Yasir Hassan ◽  
...  
Keyword(s):  
Negative Predictive Value ◽  
Predictive Value ◽  
Point Of Care ◽  
High Sensitivity ◽  
Smear Microscopy ◽  
Diagnostic Validity ◽  
Standard Material ◽  
Point Of Care Test ◽  
Resource Limited ◽  
Attractive Point

Background: Diagnosis of Tubercles Pericarditis and Pleuritis remains thegreatest challenge for clinicians. WHO has recommended GeneXpert MTB/RIF assay as ascreening test for substitution of conventional methods for the initial diagnosis and prognosisof the extra pulmonary and pulmonary tuberculosis in developing countries. Objectives: Tofind out the diagnostic validity of GeneXpert assay for detection of Myco-bacterium tuberculosisin the pericardial and pleural effusions samples, keeping MTB culture as “Gold Standard”.Material and Methods: Total number of 286 samples of effusions (pericardial 128, pleural 158)were received, and processed for Zn smear microscopy, LJ culture, GeneXpert MTB/RIF assayaccording standard protocols. Efficacy for the detection of MTB was evaluated comparatively.Results: Out of 286effusions samples AFB was detected by Zn smear in 11 (3.8%) samples whileGeneXpert detected MTB in 43 (15.0%) and LJ culture 51 (17.8%). Zn smear showed sensitivity18.2%, specificity, 98.1%, Positive predictive value 81.8%, Negative predictive value 85.4 %, incomparison GeneXpert showed high sensitivity 84.3%, specificity 100%, with Positive predictivevalue 100%, and Negative predictive value 96.7%. Conclusion: GeneXpert assay is innovativetool in resource limited settings for prompt detection of MTB along with drug résistance. It isdefinitely an attractive point of care test, with High sensitivity and specificity along with turnouttime of two hours which facilitates timely diagnoses and appropriate management of tuberclePleuritis and Pericarditis.

scholarly journals Smart Integrated Sensor for Multiple Detections of Glucose and L-Lactate Using On-Chip Electrochemical System

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Tomoyuki Yamazaki ◽  
Takaaki Ikeda ◽  
Byounghyun Lim ◽  
Koichi Okumura ◽  
Makoto Ishida ◽  
...  
Keyword(s):  
Point Of Care ◽  
Reference Electrode ◽  
Electrochemical Sensing ◽  
Quantitative Detection ◽  
Enzymatic Reactions ◽  
Single Chip ◽  
Lactate Oxidase ◽  
Integrated Sensor ◽  
System L ◽  
On Chip

Multiple sensor electrodes, a supplementary electrode, a reference electrode, and signal-processing circuits were integrated on a single chip to develop a chip-shaped electrochemical sensing system. L-lactate and glucose were measured using on-chip working electrodes modified by polyion complex to immobilize lactate oxidase and glucose oxidase, respectively. Cyclic voltammetry measurements were conducted using an on-chip potentiostat. Selective and quantitative detection of glucose and L-lactate and the interference behavior were studied. Hydrogen peroxide generated by enzymatic reactions was detected by an increase in anodic oxidation current. Reaction currents at +0.7 V versus Ag/AgCl were used to obtain calibration plots. The measured dynamic ranges for L-lactate and glucose were 0.2–1.0 mM and 2.0–8.0 mM, respectively. The sensitivities were 65 nA/mM and 15 nA/mM, respectively, using a working electrode of 0.5 mm2. The 3σdetection limit was 0.19 mM and 1.1 mM, respectively. We have achieved multiple biomaterial detections on a circuit-equipped single chip. This integrated electrochemical sensor chip could be the best candidate for realizing point-of-care testing due to its portability and potential for mass production.

scholarly journals Polymer Brush Coating and Adhesion Technology at Scale

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1475 ◽  
Author(s):  
Kristian Birk Buhl ◽  
Asger Holm Agergaard ◽  
Mie Lillethorup ◽  
Jakob Pagh Nikolajsen ◽  
Steen Uttrup Pedersen ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
High Performance ◽  
Large Scale ◽  
Polymer Brush ◽  
Dissimilar Materials ◽  
Industrial Applications ◽  
Polymer Materials ◽  
Full Potential ◽  
Scale Production ◽  
Precise Control

Creating strong joints between dissimilar materials for high-performance hybrid products places high demands on modern adhesives. Traditionally, adhesion relies on the compatibility between surfaces, often requiring the use of primers and thick bonding layers to achieve stable joints. The coatings of polymer brushes enable the compatibilization of material surfaces through precise control over surface chemistry, facilitating strong adhesion through a nanometer-thin layer. Here, we give a detailed account of our research on adhesion promoted by polymer brushes along with examples from industrial applications. We discuss two fundamentally different adhesive mechanisms of polymer brushes, namely (1) physical bonding via entanglement and (2) chemical bonding. The former mechanism is demonstrated by e.g., the strong bonding between poly(methyl methacrylate) (PMMA) brush coated stainless steel and bulk PMMA, while the latter is shown by e.g., the improved adhesion between silicone and titanium substrates, functionalized by a hydrosilane-modified poly(hydroxyethyl methacrylate) (PHEMA) brush. This review establishes that the clever design of polymer brushes can facilitate strong bonding between metals and various polymer materials or compatibilize fillers or nanoparticles with otherwise incompatible polymeric matrices. To realize the full potential of polymer brush functionalized materials, we discuss the progress in the synthesis of polymer brushes under ambient and scalable industrial conditions, and present recent developments in atom transfer radical polymerization for the large-scale production of brush-modified materials.

scholarly journals Detector-Free Photothermal Bar-Chart Microfluidic Chips (PT-Chips) for Visual Quantitative Detection of Biomarkers

2021 ◽  
Author(s):  
Wan Zhou ◽  
Guanglei Fu [email protected] ◽  
Xiujun Li
Keyword(s):  
Whole Blood ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Clinical Diagnostics ◽  
Detection Sensitivity ◽  
Quantitative Detection ◽  
Microfluidic Chips ◽  
Analytical Instruments ◽  
Photothermal Effects ◽  
On Chip

<p>The volumetric bar-chart microfluidic chips (V-Chips) driven by chemical reaction-generated gas provide a promising platform for point-of-care (POC) visual biomarker quantitation. However, multiple limitations are encountered in conventional V-Chips, such as costly and complex chip fabrication, complicated assembly, and imprecise controllability of gas production. Herein, we introduced nanomaterial-mediated photothermal effects to V-Chips, and for the first time developed a new type of V-Chip, <u>p</u>hoto<u>t</u>hermal bar-chart microfluidic <u>c</u>hip (PT-Chip), for visual quantitative detection of biochemicals without any bulky and costly analytical instruments. Immunosensing signals were converted to visual readout signals via photothermal effects, the on-chip bar-chart movements, enabling quantitative biomarker detection on a low-cost polymer hybrid PT-Chip with on-chip scale rulers. Four different human serum samples containing prostate-specific antigen (PSA) as a model analyte were detected simultaneously using the PT-Chip, with the limit of detection of 2.1 ng/mL, meeting clinical diagnostic requirements. Although no conventional signal detectors were used, it achieved comparable detection sensitivity to absorbance measurements with a microplate reader. The PT-Chip was further validated by testing human whole blood without the color interference problem, demonstrating good analytical performance of our method even in complex matrixes and thus the potential to fill a gap in current clinical diagnostics that is incapable of testing whole blood. This new PT-Chip driven by nanomaterial-mediated photothermal effects opens a new horizon of microfluidic platforms for instrument-free diagnostics at the point of care.</p>

scholarly journals Detector-Free Photothermal Bar-Chart Microfluidic Chips (PT-Chips) for Visual Quantitative Detection of Biomarkers

2021 ◽  
Author(s):  
Wan Zhou ◽  
Guanglei Fu [email protected] ◽  
Xiujun Li
Keyword(s):  
Whole Blood ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Clinical Diagnostics ◽  
Detection Sensitivity ◽  
Quantitative Detection ◽  
Microfluidic Chips ◽  
Analytical Instruments ◽  
Photothermal Effects ◽  
On Chip

<p>The volumetric bar-chart microfluidic chips (V-Chips) driven by chemical reaction-generated gas provide a promising platform for point-of-care (POC) visual biomarker quantitation. However, multiple limitations are encountered in conventional V-Chips, such as costly and complex chip fabrication, complicated assembly, and imprecise controllability of gas production. Herein, we introduced nanomaterial-mediated photothermal effects to V-Chips, and for the first time developed a new type of V-Chip, <u>p</u>hoto<u>t</u>hermal bar-chart microfluidic <u>c</u>hip (PT-Chip), for visual quantitative detection of biochemicals without any bulky and costly analytical instruments. Immunosensing signals were converted to visual readout signals via photothermal effects, the on-chip bar-chart movements, enabling quantitative biomarker detection on a low-cost polymer hybrid PT-Chip with on-chip scale rulers. Four different human serum samples containing prostate-specific antigen (PSA) as a model analyte were detected simultaneously using the PT-Chip, with the limit of detection of 2.1 ng/mL, meeting clinical diagnostic requirements. Although no conventional signal detectors were used, it achieved comparable detection sensitivity to absorbance measurements with a microplate reader. The PT-Chip was further validated by testing human whole blood without the color interference problem, demonstrating good analytical performance of our method even in complex matrixes and thus the potential to fill a gap in current clinical diagnostics that is incapable of testing whole blood. This new PT-Chip driven by nanomaterial-mediated photothermal effects opens a new horizon of microfluidic platforms for instrument-free diagnostics at the point of care.</p>

Multicountry Validation of SAMBA - A Novel Molecular Point-of-Care Test for HIV-1 Detection in Resource-Limited Setting

2017 ◽  
Vol 76 (2) ◽  
pp. e52-e57 ◽  
Author(s):  
Johnson Ondiek ◽  
Zikulah Namukaya ◽  
Sekesai Mtapuri-Zinyowera ◽  
Suna Balkan ◽  
Ali Elbireer ◽  
...  
Keyword(s):  
Point Of Care ◽  
Resource Limited Setting ◽  
Point Of Care Test ◽  
Resource Limited ◽  
Hiv 1 ◽  
Limited Setting

scholarly journals GPU Accelerated Adaptive Banded Event Alignment for Rapid Comparative Nanopore Signal Analysis

2019 ◽  
Author(s):  
Hasindu Gamaarachchi ◽  
Chun Wai Lam ◽  
Gihan Jayatilaka ◽  
Hiruna Samarakoon ◽  
Jared T. Simpson ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Embedded System ◽  
High Performance ◽  
Point Of Care ◽  
Dynamic Programming Algorithm ◽  
Reference Sequence ◽  
Programming Algorithm ◽  
Sequencing Data ◽  
On Chip ◽  
Gpu Architectures

AbstractNanopore sequencing has the potential to revolutionise genomics by realising portable, real-time sequencing applications, including point-of-care diagnostics and in-the-field genotyping. Achieving these applications requires efficient bioinformatic algorithms for the analysis of raw nanopore signal data. For instance, comparing raw nanopore signals to a biological reference sequence is a computationally complex task despite leveraging a dynamic programming algorithm for Adaptive Banded Event Alignment (ABEA)—a commonly used approach to polish sequencing data and identify non-standard nucleotides, such as measuring DNA methylation. Here, we parallelise and optimise an implementation of the ABEA algorithm (termed f5c) to efficiently run on heterogeneous CPU-GPU architectures. By optimising memory, compute and load balancing between CPU and GPU, we demonstrate how f5c can perform ~3-5× faster than the original implementation of ABEA in the Nanopolish software package. We also show that f5c enables DNA methylation detection on-the-fly using an embedded System on Chip (SoC) equipped with GPUs. Our work not only demonstrates that complex genomics analyses can be performed on lightweight computing systems, but also benefits High-Performance Computing (HPC). The associated source code for f5c along with GPU optimised ABEA is available at https://github.com/hasindu2008/f5c.

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