scholarly journals Biosensing on the Centrifugal Microfluidic Lab-on-a-Disc Platform

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1360
Author(s):  
Celina M. Miyazaki ◽  
Eadaoin Carthy ◽  
David J. Kinahan

Lab-on-a-Disc (LoaD) biosensors are increasingly a promising solution for many biosensing applications. In the search for a perfect match between point-of-care (PoC) microfluidic devices and biosensors, the LoaD platform has the potential to be reliable, sensitive, low-cost, and easy-to-use. The present global pandemic draws attention to the importance of rapid sample-to-answer PoC devices for minimising manual intervention and sample manipulation, thus increasing the safety of the health professional while minimising the chances of sample contamination. A biosensor is defined by its ability to measure an analyte by converting a biological binding event to tangible analytical data. With evolving manufacturing processes for both LoaDs and biosensors, it is becoming more feasible to embed biosensors within the platform and/or to pair the microfluidic cartridges with low-cost detection systems. This review considers the basics of the centrifugal microfluidics and describes recent developments in common biosensing methods and novel technologies for fluidic control and automation. Finally, an overview of current devices on the market is provided. This review will guide scientists who want to initiate research in LoaD PoC devices as well as providing valuable reference material to researchers active in the field.

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 189
Author(s):  
Susana Campuzano ◽  
Paloma Yáñez-Sedeño ◽  
José Manuel Pingarrón

The multifaceted key roles of cytokines in immunity and inflammatory processes have led to a high clinical interest for the determination of these biomolecules to be used as a tool in the diagnosis, prognosis, monitoring and treatment of several diseases of great current relevance (autoimmune, neurodegenerative, cardiac, viral and cancer diseases, hypercholesterolemia and diabetes). Therefore, the rapid and accurate determination of cytokine biomarkers in body fluids, cells and tissues has attracted considerable attention. However, many currently available techniques used for this purpose, although sensitive and selective, require expensive equipment and advanced human skills and do not meet the demands of today’s clinic in terms of test time, simplicity and point-of-care applicability. In the course of ongoing pursuit of new analytical methodologies, electrochemical biosensing is steadily gaining ground as a strategy suitable to develop simple, low-cost methods, with the ability for multiplexed and multiomics determinations in a short time and requiring a small amount of sample. This review article puts forward electrochemical biosensing methods reported in the last five years for the determination of cytokines, summarizes recent developments and trends through a comprehensive discussion of selected strategies, and highlights the challenges to solve in this field. Considering the key role demonstrated in the last years by different materials (with nano or micrometric size and with or without magnetic properties), in the design of analytical performance-enhanced electrochemical biosensing strategies, special attention is paid to the methods exploiting these approaches.


2005 ◽  
Vol 51 (10) ◽  
pp. 1923-1932 ◽  
Author(s):  
Michael J Pugia ◽  
Gert Blankenstein ◽  
Ralf-Peter Peters ◽  
James A Profitt ◽  
Klaus Kadel ◽  
...  

Abstract Background: Use of microfluidics in point-of-care testing (POCT) will require on-board fluidics, self-contained reagents, and multistep reactions, all at a low cost. Disposable microchips were studied as a potential POCT platform. Methods: Micron-sized structures and capillaries were embedded in disposable plastics with mechanisms for fluidic control, metering, specimen application, separation, and mixing of nanoliter to microliter volumes. Designs allowed dry reagents to be on separate substrates and liquid reagents to be added. Control of surface energy to ±5 dyne/cm2 and mechanical tolerances to ≤1 μm were used to control flow propulsion into adsorptive, chromatographic, and capillary zones. Fluidic mechanisms were combined into working examples for urinalysis, blood glucose, and hemoglobin A1c testing using indicators (substances that react with analyte, such as dyes, enzyme substrates, and diazonium salts), catalytic reactions, and antibodies as recognition components. Optical signal generation characterized fluid flow and allowed detection. Results: We produced chips that included capillary geometries from 10 to 200 μm with geometries for stopping and starting the flow of blood, urine, or buffer; vented chambers for metering and splitting 100 nL to 30 μL; specimen inlets for bubble-free specimen entry and containment; capillary manifolds for mixing; microstructure interfaces for homogeneous transfer into separation membranes; miniaturized containers for liquid storage and release; and moisture vapor barrier seals for easy use. Serum was separated from whole blood in <10 s. Miniaturization benefits were obtained at 10–200 μm. Conclusion: Disposable microchip technology is compatible with conventional dry-reagent technology and allows a highly compact system for complex assay sequences with minimum manual manipulations and simple operation.


2019 ◽  
Vol 21 (1) ◽  
pp. 134 ◽  
Author(s):  
Wei Xu ◽  
Daniel Wang ◽  
Derek Li ◽  
Chung Chiun Liu

Detection of biomarkers has raised much interest recently due to the need for disease diagnosis and personalized medicine in future point-of-care systems. Among various biomarkers, antibodies are an important type of detection target due to their potential for indicating disease progression stage and the efficiency of therapeutic antibody drug treatment. In this review, electrochemical and optical detection of antibodies are discussed. Specifically, creating a non-label and reagent-free sensing platform and construction of an anti-fouling electrochemical surface for electrochemical detection are suggested. For optical transduction, a rapid and programmable platform for antibody detection using a DNA-based beacon is suggested as well as the use of bioluminescence resonance energy transfer (BRET) switch for low cost antibody detection. These sensing strategies have demonstrated their potential for resolving current challenges in antibody detection such as high selectivity, low operation cost, simple detection procedures, rapid detection, and low-fouling detection. This review provides a general update for recent developments in antibody detection strategies and potential solutions for future clinical point-of-care systems.


Author(s):  
Michael R. Moon ◽  
Lin Lin

Point of care medical instruments benefit from compact fluid handling systems in the microliter range. To handle fluid volumes this small, many novel technologies have been studied. Pneumatic valves offer advantages over other microfluidic valves, including robustness and low cost. These valves are used in centrifugal microfluidic devices, a very active area of research, and take advantage of pneumatic and centrifugal pressure to aliquot and control the flow of fluid. The physics of fluids at the micrometer scale are complex and modelling their behavior using CFD software is challenging. Representing adhesion, surface tension, and other multiphase interactions is critical to accurately model microfluidic behavior. Centrifugal devices must also consider Coriolis, centrifugal, and Euler effects. In this study, a pneumatic valve was designed and simulated using commercial CFD software. The device was also fabricated for verification of the simulation. The simulation demonstrated the multiphase interactions of fluid and air within the rotating device. In a transient analysis of the model, a 6 μl volume of water is held in stable equilibrium by a compressed volume of air at low RPM, while at a higher RPM, the fluid is observed to displace the compressed air as a result of Rayleigh-Taylor instability. Actual devices with comparable geometry were built and tested. The behavior of the valve predicted in the model was in agreement with experimental results produced from the actual devices. The results of the simulation captured the stabilizing effect of both pneumatic pressure and surface tension at low RPM, as well as the instability that results from increased centrifugal and Euler pressure at higher RPM.


2020 ◽  
Author(s):  
Ilkay Cisil Koksaldi ◽  
Recep Erdem Ahan ◽  
Sila Kose ◽  
Nedim Haciosmanoglu ◽  
Ebru Sahin Kehribar ◽  
...  

Sars-CoV-2 is a human pathogen and is the main cause of COVID-19 disease. COVID-19 is announced as a global pandemic by World Health Organization. COVID-19 is characterized by severe conditions and early diagnosis can make dramatic changes both for personal and public health. In order to increase the reach for low cost equipment which requires a very limited technical knowledge can be beneficial to diagnose the viral infection. Such diagnostic capabilities can have a very critical role to control the transmission of the disease. Here we are reporting a state-of-the-art diagnostic tool developed by using an in vitro synthetic biology approach by employing engineered de novo riboregulators. Our design coupled with a home-made point-of-care device setting can detect and report presence of Sars-CoV-2 specific genes. The presence of Sars-CoV-2 related genes triggers translation of sfGFP mRNAs, resulting in green fluorescence output. The approach proposed here has the potential of being a game changer in Sars-COV-2 diagnostics by providing an easy-to-run, low-cost-demanding diagnostic capability.


2021 ◽  
Vol 9 (1) ◽  
pp. 7-12
Author(s):  
T Prasanth ◽  
Sumita Manandhar ◽  
Satisha T S ◽  
Pramod Kumar

Periodontitis is chronic inflammation of the periodontium caused by persistent bacterial infection affecting the connective tissue attachment and supporting bone around the teeth. As the ability to reconstruct the periodontium is limited after alveolar bone loss, early diagnosis and intervention should be paramount goals of periodontal treatment preventing future disease’s progression. Saliva is a physiologic fluid that contains complex mixture of substances as well as inflammatory biomarkers associated with periodontitis. Conventional clinical criteria are often insufficient for determining sites of active disease, for monitoring the response to therapy, or for measuring the degree of susceptibility to future disease progression. Therefore, the use of saliva has provided a substantial addition to the diagnostic armamentarium as an investigative tool for disease processes. With the current technological advances, together with point-of-care detection systems, salivary analysis will be valued much more highly in the near future. Even though saliva is easy to manipulate with low-cost storage, careful attention must be directed to limit variation in specimen integrity. This review focuses on the biomarkers in saliva that appears to be promising in the future for periodontal diagnosis, as well as some contemporary diagnostic tests available.


Author(s):  
Parinaz Fozouni ◽  
Sungmin Son ◽  
María Díaz de León Derby ◽  
Gavin J Knott ◽  
Carley N Gray ◽  
...  

The December 2019 outbreak of a novel respiratory virus, SARS-CoV-2, has become an ongoing global pandemic due in part to the challenge of identifying symptomatic, asymptomatic and pre- symptomatic carriers of the virus. CRISPR-based diagnostics that utilize RNA and DNA-targeting enzymes can augment gold-standard PCR-based testing if they can be made rapid, portable and accurate. Here we report the development of an amplification-free CRISPR-Cas13a-based mobile phone assay for direct detection of SARS-CoV-2 from nasal swab RNA extracts. The assay achieved ~100 copies/μL sensitivity in under 30 minutes and accurately detected a set of positive clinical samples in under 5 minutes. We combined crRNAs targeting SARS-CoV-2 RNA to improve sensitivity and specificity, and we directly quantified viral load using enzyme kinetics. Combined with mobile phone-based quantification, this assay can provide rapid, low-cost, point-of-care screening to aid in the control of SARS-CoV-2.


2019 ◽  
Vol 11 (4) ◽  
pp. 314-315
Author(s):  
James S Leathers ◽  
Maria Belen Pisano ◽  
Viviana Re ◽  
Gertine van Oord ◽  
Amir Sultan ◽  
...  

Abstract Background Treatment of HCV with direct-acting antivirals has enabled the discussion of HCV eradication worldwide. Envisioning this aim requires implementation of mass screening in resource-limited areas, usually constrained by testing costs. Methods We validated a low-cost, rapid diagnosis test (RDT) for HCV in three different continents in 141 individuals. Results The HCV RDT showed 100% specificity and sensitivity across different samples regardless of genotype or viral load (in samples with such information, 90%). Conclusions The HCV test validated in this study can allow for HCV screening in areas of need when properly used.


Author(s):  
Thomas A Lewis

Abstract As a discipline, the academic study of religion is strikingly fragmented, with little engagement or shared criteria of excellence across subfields. Although important recent developments have expanded the traditions and peoples studied as well as the methods used, the current extent of fragmentation limits the impact of this diversification and pluralization. At a moment when the global pandemic is catalyzing profound pressures on our universities and disciplines, this fragmentation makes it difficult to articulate to the public, to non-religious studies colleagues, and to students why the study of religion matters. We therefore too often fall back on platitudes. I argue for a revitalized methods and theories conversation that connects us even as it bears our arguments and disagreements about what we do and how. Courses in methods and theories in the study of religion represent the most viable basis we have for bringing the academic study of religion into the common conversation or argument that constitutes a discipline without sacrificing our pluralism.


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