scholarly journals A versatile capillaric microfluidics viscometer platform for bar-graph type point-of-care diagnostics

2021 ◽  
Author(s):  
Robert Claude Meffan ◽  
Julian Menges ◽  
Fabian Dolamore ◽  
Daniel Mak ◽  
Conan Fee ◽  
...  
Keyword(s):  
Field Effect Transistors ◽  
Point Of Care ◽  
Relative Viscosity ◽  
Microfluidic Channel ◽  
Flow Paths ◽  
Capillary Action ◽  
Point Of Care Diagnostics ◽  
Graph Type ◽  
Poly Ethylene ◽  
And Performance

A novel capillary action microfluidic viscometer has been designed that can measure the relative viscosity of a sample compared to a control liquid. Using capillary action circuits, the viscosity of a sample is transformed into a microfluidic bar-graph format without the use of external instrumentation. The bars in this case are represented by the distance that a liquid has flown through a microfluidic channel, relative to another liquid in an identical channel. As the device does not require external instrumentation, its use is targeted at point-of-care (PoC) situations. This implementation is made practical through capillaric Field Effect Transistors, and the conditional flow paths they enable. In this paper, we report on the design, operation, and performance of a two-channel version viscometer device exclusively based on capillary action circuits. Using poly-ethylene glycol solutions as viscous samples, we demonstrate that the device can transduce the relative viscosity consistently to within 2%. Enabled by the flexibility of the capillary action circuits, we additionally present a modified device which can measure transparent liquids without the need to add colorants to the sample. The forms of the device presented in this work have applications in both medical care and scientific measurements—particularly for PoC measurements.

scholarly journals Design and Fabrication of Capillary-Driven Flow Device for Point-Of-Care Diagnostics

Biosensors ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 39 ◽  
Author(s):  
Sammer-ul Hassan ◽  
Xunli Zhang
Keyword(s):  
Point Of Care ◽  
Capillary Action ◽  
Point Of Care Diagnostics ◽  
Flow Device ◽  
Working Principle ◽  
Complex Fluid

Point-of-care (POC) diagnostics enables the diagnosis and monitoring of patients from the clinic or their home. Ideally, POC devices should be compact, portable and operatable without the requirement of expertise or complex fluid mechanical controls. This paper showcases a chip-and-dip device, which works on the principle of capillary-driven flow microfluidics and allows analytes’ detection by multiple microchannels in a single microchip via smartphone imaging. The chip-and-dip device, fabricated with inexpensive materials, works by simply dipping the reagents-coated microchip consisting of microchannels into a fluidic sample. The sample is loaded into the microchannels via capillary action and reacts with the reagents to produce a colourimetric signal. Unlike dipstick tests, this device allows the loading of bacterial/pathogenic samples for antimicrobial testing. A single device can be coated with multiple reagents, and more analytes can be detected in one sample. This platform could be used for a wide variety of assays. Here, we show the design, fabrication and working principle of the chip-and-dip flow device along with a specific application consisting in the determination of β-lactamase activity and cortisol. The simplicity, robustness and multiplexing capability of the chip-and-dip device will allow it to be used for POC diagnostics.

scholarly journals ImmunoFET feasibility in physiological salt environments

2012 ◽  
Vol 370 (1967) ◽  
pp. 2474-2488 ◽  
Author(s):  
Patricia Casal ◽  
Xuejin Wen ◽  
Samit Gupta ◽  
Theodore Nicholson ◽  
Yuji Wang ◽  
...  
Keyword(s):  
Field Effect Transistors ◽  
Point Of Care ◽  
Charge Carriers ◽  
Protein Species ◽  
Related Protein ◽  
Limited Sample ◽  
Protein Sensing ◽  
Point Of Care Diagnostics ◽  
Electrical Devices ◽  
Protein Sensors

Field-effect transistors (FETs) are solid-state electrical devices featuring current sources, current drains and semiconductor channels through which charge carriers migrate. FETs can be inexpensive, detect analyte without label, exhibit exponential responses to surface potential changes mediated by analyte binding, require limited sample preparation and operate in real time. ImmunoFETs for protein sensing deploy bioaffinity elements on their channels (antibodies), analyte binding to which modulates immunoFET electrical properties. Historically, immunoFETs were assessed infeasible owing to ion shielding in physiological environments. We demonstrate reliable immunoFET sensing of chemokines by relatively ion-impermeable III-nitride immunoHFETs (heterojunction FETs) in physiological buffers. Data show that the specificity of detection follows the specificity of the antibodies used as receptors, allowing us to discriminate between individual highly related protein species (human and murine CXCL9) as well as mixed samples of analytes (native and biotinylated CXCL9). These capabilities demonstrate that immunoHFETs can be feasible, contrary to classical FET-sensing assessment. FET protein sensors may lead to point-of-care diagnostics that are faster and cheaper than immunoassay in clinical, biotechnological and environmental applications.

scholarly journals Process-property correlations in laser-induced graphene electrodes for electrochemical sensing

2021 ◽  
Vol 188 (5) ◽  
Author(s):  
Arne Behrent ◽  
Christian Griesche ◽  
Paul Sippel ◽  
Antje J. Baeumner
Keyword(s):  
Energy Input ◽  
Point Of Care ◽  
Low Cost ◽  
High Energy ◽  
Fabrication Process ◽  
Electrochemical Sensing ◽  
Point Of Care Diagnostics ◽  
Pulse Density ◽  
Binder Free ◽  
And Performance

AbstractLaser-induced graphene (LIG) has emerged as a promising electrode material for electrochemical point-of-care diagnostics. LIG offers a large specific surface area and excellent electron transfer at low-cost in a binder-free and rapid fabrication process that lends itself well to mass production outside of the cleanroom. Various LIG micromorphologies can be generated when altering the energy input parameters, and it was investigated here which impact this has on their electroanalytical characteristics and performance. Energy input is well controlled by the laser power, scribing speed, and laser pulse density. Once the threshold of required energy input is reached a broad spectrum of conditions leads to LIG with micromorphologies ranging from delicate irregular brush structures obtained at fast, high energy input, to smoother and more wall like albeit still porous materials. Only a fraction of these LIG structures provided high conductance which is required for appropriate electroanalytical performance. Here, it was found that low, frequent energy input provided the best electroanalytical material, i.e., low levels of power and speed in combination with high spatial pulse density. For example, the sensitivity for the reduction of K3[Fe(CN)6] was increased almost 2-fold by changing fabrication parameters from 60% power and 100% speed to 1% power and 10% speed. These general findings can be translated to any LIG fabrication process independent of devices used. The simple fabrication process of LIG electrodes, their good electroanalytical performance as demonstrated here with a variety of (bio)analytically relevant molecules including ascorbic acid, dopamine, uric acid, p-nitrophenol, and paracetamol, and possible application to biological samples make them ideal and inexpensive transducers for electrochemical (bio)sensors, with the potential to replace the screen-printed systems currently dominating in on-site sensors used. Graphical abstract

scholarly journals COVID-19 Point-of-Care Diagnostics: Present and Future

ACS Nano ◽  
2021 ◽  
Author(s):  
Enrique Valera ◽  
Aaron Jankelow ◽  
Jongwon Lim ◽  
Victoria Kindratenko ◽  
Anurup Ganguli ◽  
...  
Keyword(s):  
Point Of Care ◽  
Point Of Care Diagnostics

scholarly journals 145 Point of care lung ultrasound in patient triage: integration of ultrasound into a streaming pathway for COVID-19

2020 ◽  
Vol 37 (12) ◽  
pp. 839.1-839
Author(s):  
Dominic Craver ◽  
Aminah Ahmad ◽  
Anna Colclough
Keyword(s):  
Point Of Care ◽  
District General Hospital ◽  
Training Programme ◽  
Service Evaluation ◽  
University Hospital ◽  
Junior Doctors ◽  
Point Of Care Ultrasound ◽  
Face To Face ◽  
Point Of Care Diagnostics ◽  
Audit Data

Aims/Objectives/BackgroundRapid risk stratification of patients is vital for Emergency Department (ED) streaming during the COVID-19 pandemic. Ideally, patients should be split into red (suspected/confirmed COVID-19) and green (non COVID-19) zones in order to minimise the risk of patient-to-patient and patient-to-staff transmission. A robust yet rapid streaming system combining clinician impression with point-of-care diagnostics is therefore necessary.Point of care ultrasound (POCUS) findings in COVID-19 have been shown to correlate well with computed tomography (CT) findings, and it therefore has value as a front-door diagnostic tool. At University Hospital Lewisham (a district general hospital in south London), we recognised the value of early POCUS and its potential for use in patient streaming.Methods/DesignWe developed a training programme, ‘POCUS for COVID’ and subsequently integrated POCUS into streaming of our ED patients. The training involved Zoom lectures, a face to face practical, a 10 scan sign off process followed by a final triggered assessment. Patient outcomes were reviewed in conjunction with their scan reports.Results/ConclusionsCurrently, we have 21 ED junior doctors performing ultrasound scans independently, and all patients presenting to our department are scanned either in triage or in the ambulance. A combination of clinical judgement and scan findings are used to stream the patient to an appropriate area.Service evaluation with analysis of audit data has found our streaming to be 94% sensitive and 79% specific as an indicator of COVID 19. Further analysis is ongoing.Here we present both the structure of our training programme and our integrated streaming pathway along with preliminary analysis results.

scholarly journals Point of Care Diagnostics in the Age of COVID-19

Diagnostics ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 9
Author(s):  
Meysam Rezaei ◽  
Sajad Razavi Bazaz ◽  
Sareh Zhand ◽  
Nima Sayyadi ◽  
Dayong Jin ◽  
...  
Keyword(s):  
Point Of Care ◽  
Diagnostic Methods ◽  
Global Public Health ◽  
Current Standard ◽  
Healthcare Facilities ◽  
Major Threat ◽  
Point Of Care Diagnostics ◽  
Recent Outbreak ◽  
Control Virus ◽  
Biosafety Level

The recent outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its associated serious respiratory disease, coronavirus disease 2019 (COVID-19), poses a major threat to global public health. Owing to the lack of vaccine and effective treatments, many countries have been overwhelmed with an exponential spread of the virus and surge in the number of confirmed COVID-19 cases. Current standard diagnostic methods are inadequate for widespread testing as they suffer from prolonged turn-around times (>12 h) and mostly rely on high-biosafety-level laboratories and well-trained technicians. Point-of-care (POC) tests have the potential to vastly improve healthcare in several ways, ranging from enabling earlier detection and easier monitoring of disease to reaching remote populations. In recent years, the field of POC diagnostics has improved markedly with the advent of micro- and nanotechnologies. Due to the COVID-19 pandemic, POC technologies have been rapidly innovated to address key limitations faced in existing standard diagnostic methods. This review summarizes and compares the latest available POC immunoassay, nucleic acid-based and clustered regularly interspaced short palindromic repeats- (CRISPR)-mediated tests for SARS-CoV-2 detection that we anticipate aiding healthcare facilities to control virus infection and prevent subsequent spread.

scholarly journals Pocket MUSE: an affordable, versatile and high-performance fluorescence microscope using a smartphone

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yehe Liu ◽  
Andrew M. Rollins ◽  
Richard M. Levenson ◽  
Farzad Fereidouni ◽  
Michael W. Jenkins
Keyword(s):  
High Performance ◽  
Point Of Care ◽  
Low Cost ◽  
Consumer Electronics ◽  
Practical Implementation ◽  
The Novel ◽  
Point Of Care Diagnostics ◽  
Optical Module ◽  
Optical Configuration ◽  
User Friendly

AbstractSmartphone microscopes can be useful tools for a broad range of imaging applications. This manuscript demonstrates the first practical implementation of Microscopy with Ultraviolet Surface Excitation (MUSE) in a compact smartphone microscope called Pocket MUSE, resulting in a remarkably effective design. Fabricated with parts from consumer electronics that are readily available at low cost, the small optical module attaches directly over the rear lens in a smartphone. It enables high-quality multichannel fluorescence microscopy with submicron resolution over a 10× equivalent field of view. In addition to the novel optical configuration, Pocket MUSE is compatible with a series of simple, portable, and user-friendly sample preparation strategies that can be directly implemented for various microscopy applications for point-of-care diagnostics, at-home health monitoring, plant biology, STEM education, environmental studies, etc.

scholarly journals Microfluidics-Based Plasmonic Biosensing System Based on Patterned Plasmonic Nanostructure Arrays

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 826
Author(s):  
Yanting Liu ◽  
Xuming Zhang
Keyword(s):  
Plasmon Resonance ◽  
Point Of Care ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Microfluidic Chips ◽  
Label Free ◽  
Plasmonic Nanostructure ◽  
Point Of Care Diagnostics ◽  
Surface Enhanced Raman ◽  
Nanostructure Arrays

This review aims to summarize the recent advances and progress of plasmonic biosensors based on patterned plasmonic nanostructure arrays that are integrated with microfluidic chips for various biomedical detection applications. The plasmonic biosensors have made rapid progress in miniaturization sensors with greatly enhanced performance through the continuous advances in plasmon resonance techniques such as surface plasmon resonance (SPR) and localized SPR (LSPR)-based refractive index sensing, SPR imaging (SPRi), and surface-enhanced Raman scattering (SERS). Meanwhile, microfluidic integration promotes multiplexing opportunities for the plasmonic biosensors in the simultaneous detection of multiple analytes. Particularly, different types of microfluidic-integrated plasmonic biosensor systems based on versatile patterned plasmonic nanostructured arrays were reviewed comprehensively, including their methods and relevant typical works. The microfluidics-based plasmonic biosensors provide a high-throughput platform for the biochemical molecular analysis with the advantages such as ultra-high sensitivity, label-free, and real time performance; thus, they continue to benefit the existing and emerging applications of biomedical studies, chemical analyses, and point-of-care diagnostics.

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