scholarly journals Manipulation of Magnetic Beads with Thin Film Microelectromagnet Traps

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 607 ◽  
Author(s):  
Vania Silverio ◽  
Miguel Amaral ◽  
João Gaspar ◽  
Susana Cardoso ◽  
Paulo P. Freitas
Keyword(s):  
Real Time ◽  
Magnetic Beads ◽  
Cooling System ◽  
Point Of Care ◽  
Cost Effective ◽  
Local Concentration ◽  
Effective Care ◽  
In Series ◽  
Microfluidic Flows ◽  
System Variables

Integration of point-of-care assays can be facilitated with the use of actuated magnetic beads (MB) to perform testing in less expensive settings to enable the delivery of cost-effective care. In this paper we present six different designs of planar microelectromagnets traps (MEMT) with four external coils in series and one central coil connected for an opposite direction of manipulation of MB in microfluidic flows. The development of a simulation tool facilitated the rapid and efficient optimization of designs by presenting the influence of system variables on real time concentrations of MB. Real time experiments are in good agreement with the simulations and showed that the design enabled synchronous concentration and dispersion of MB on the same MEMT. The yield of local concentration is seen to be highly dependent on coil design. Additional coil turns between the central and external coils (inter-windings) doubled magnetic concentration and repulsion with no significant electrical resistance increase. The assemblage of a copper microchannel closed loop cooling system to the coils successfully eliminated the thermal drift promoted by joule heating generated by applied current.

scholarly journals Development of a Diagnostic Biosensor Method of Hypersensitivity Pneumonitis towards a Point-of-Care Biosensor

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 196
Author(s):  
Tatiana Fiordelisio ◽  
Ivette Buendia-Roldan ◽  
Mathieu Hautefeuille ◽  
Diana Del-Rio ◽  
Diana G. Ríos-López ◽  
...  
Keyword(s):  
Hypersensitivity Pneumonitis ◽  
Magnetic Beads ◽  
Point Of Care ◽  
Cost Effective ◽  
High Volume ◽  
Antibody Detection ◽  
Optical Detectors ◽  
Conventional Elisa ◽  
Increasing Trend ◽  
A Current

In spite of a current increasing trend in the development of miniaturized, standalone point-of-care (PoC) biosensing platforms in the literature, the actual implementation of such systems in the field is far from being a reality although deeply needed. In the particular case of the population screenings for local or regional diseases related to specific pathogens, the diagnosis of the presence of specific antibodies could drastically modify therapies and even the organization of public policies. The aim of this work was to develop a fast, cost-effective detection method based on the manipulation of functionalized magnetic beads for an efficient diagnosis of hypersensitivity pneumonitis (HP), looking for the presence of anti-pigeon antigen antibodies (APAA) in a patient’s serum. We presented a Diagnostic Biosensor Method (DBM) in detail, with validation by comparison with a traditional high-throughput platform (ELISA assay). We also demonstrated that it was compatible with a microfluidic chip that could be eventually incorporated into a PoC for easy and broad deployment using portable optical detectors. After standardization of the different reaction steps, we constructed and validated a plastic chip that could easily be scaled to high-volume manufacturing in the future. The solution proved comparable to conventional ELISA assays traditionally performed by the clinicians in their laboratory and should be compatible with other antibody detection directly from patient samples.

Reusable Surface Molecular Imprint Biosensors Aided by Naturally Occurring Surface Roughness Indices for Point-of-Care Diagnostics

MRS Advances ◽  
2019 ◽  
Vol 4 (22) ◽  
pp. 1299-1308 ◽  
Author(s):  
Yehoshua Auerbach ◽  
Rebecca Isseroff ◽  
Nicholas Clayton ◽  
Miguel Hulyalkar ◽  
Andrew Todt ◽  
...  
Keyword(s):  
Real Time ◽  
Molecular Imprinting ◽  
Point Of Care ◽  
High Sensitivity ◽  
Cost Effective ◽  
Stem Cell Differentiation ◽  
Diverse Range ◽  
Point Of Care Diagnostics ◽  
Molecular Imprint ◽  
Detection Of Biomarkers

ABSTRACTWe have shown that molecular imprinting (MI) technology can be used to produce sensitive, robust, cost-effective biosensing systems with a real-time electrochemical readout that can be utilized for point of care diagnostics. Real time detection of biomarkers is essential when rapid, critical decisions need to be made, such as in situations where public health is threatened. Our biosensor has high sensitivity compared to standard methods like ELISA, and results are obtained within minutes, using inexpensive, accessible potentiometric readout technology. These biosensors utilize surface molecular imprinting of a self-assembling monolayer of hydroxy-terminated alkanethiol chains which form a crystalline ‘lock-and-key’ structure around a target analyte, allowing the sensors to detect and differentiate between bio-macromolecules of similar size and shape with high selectivity and sensitivity. The sensors are extremely versatile and able to detect a diverse range of molecules of varied chemical composition and structure. To fully exploit the sensors’ advantages, especially in remote, economically disadvantaged areas, it is important to quantify their durability and reusability. Biosensor chips were created to test the viability of hemoglobin detection and to evaluate the potential for sensor reusability when washed after detection testing. The successful readsorption of hemoglobin even after washing, accompanied by cyclic voltammetry data indicating the preservation of the SAM, indicate that these biosensors are reusable, significantly augmenting the device’s value. Potential applications include the analysis of complex chemical and biological processes such as stem cell differentiation and on-the-spot detection of diseases such as Zika.

scholarly journals Real-time colorimetric LAMP methodology for quantitative nucleic acids detection at the point-of-care

2020 ◽  
Author(s):  
George Papadakis ◽  
Alexandros K. Pantazis ◽  
Nikolaos Fikas ◽  
Stella Chatziioannidou ◽  
Kleita Michaelidou ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Real Time ◽  
Dynamic Range ◽  
Point Of Care ◽  
Cost Effective ◽  
Detection Capability ◽  
Ability To Work ◽  
Rna Detection ◽  
Fast Prototyping ◽  
Nucleic Acids Detection

AbstractMost methods applied to nucleic acids’ detection at the point-of-care require either expensive and mostly bench-top instruments or simpler inexpensive systems providing qualitative results. Truly decentralized approaches to reliable, quantitative and affordable diagnostics are still missing. Here, we report the development of real-time quantitative colorimetric LAMP based on a portable and cost-effective device, the use of which requires minimal training. Main advantages of the method are the rapid analysis time (<30min); quantification over a large dynamic range (9 log units); ability to work with crude samples (saliva, tissue); demonstrated low detection limit (1-10 copies); smartphone-operation and fast prototyping (3D-printing). The system’s broad detection capability is demonstrated during infectious diseases-testing for COVID-19 and pharmacogenetics for BRAF V600E mutation testing. Validation studies showed 97.4% and 100% agreement with qRT-PCR for SARS-CoV-2 RNA detection extracted from positive and negative patients’ samples (89), respectively; and 100% agreement with ddPCR and Sanger sequencing for BRAF V600E mutation detection from 12 clinical biopsy samples. The new methodology provides a needed solution for affordable healthcare at the point-of-care, with emphasis on global diagnostics.

scholarly journals Towards A Graphene Chip System For Blood Clotting Disease Diagnostics

2020 ◽  
Author(s):  
◽  
Jacob J. Mitchell
Keyword(s):  
Real Time ◽  
Blood Clotting ◽  
Point Of Care ◽  
Cost Effective ◽  
Sampling Point ◽  
Sensor Platform ◽  
Disease Diagnostics ◽  
Highly Sensitive ◽  
Wide Range ◽  
Semiconductor Fabrication

Point of care diagnostics (POCD) allows the rapid, accurate measurement of analytes near to a patient. This enables faster clinical decision making and can lead to earlier diagnosis and better patient monitoring and treatment. However, despite many prospective POCD devices being developed for a wide range of diseases this promised technology is yet to be translated to a clinical setting due to the lack of a cost-effective biosensing platform.This thesis focuses on the development of a highly sensitive, low cost and scalable biosensor platform that combines graphene with semiconductor fabrication tech-niques to create graphene field-effect transistors biosensor. The key challenges of designing and fabricating a graphene-based biosensor are addressed. This work fo-cuses on a specific platform for blood clotting disease diagnostics, but the platform has the capability of being applied to any disease with a detectable biomarker.Multiple sensor designs were tested during this work that maximised sensor ef-ficiency and costs for different applications. The multiplex design enabled different graphene channels on the same chip to be functionalised with unique chemistry. The Inverted MOSFET design was created, which allows for back gated measurements to be performed whilst keeping the graphene channel open for functionalisation. The Shared Source and Matrix design maximises the total number of sensing channels per chip, resulting in the most cost-effective fabrication approach for a graphene-based sensor (decreasing cost per channel from £9.72 to £4.11).The challenge of integrating graphene into a semiconductor fabrication process is also addressed through the development of a novel vacuum transfer method-ology that allows photoresist free transfer. The two main fabrication processes; graphene supplied on the wafer “Pre-Transfer” and graphene transferred after met-allisation “Post-Transfer” were compared in terms of graphene channel resistance and graphene end quality (defect density and photoresist). The Post-Transfer pro-cess higher quality (less damage, residue and doping, confirmed by Raman spec-troscopy).Following sensor fabrication, the next stages of creating a sensor platform involve the passivation and packaging of the sensor chip. Different approaches using dielec-tric deposition approaches are compared for passivation. Molecular Vapour Deposi-tion (MVD) deposited Al2O3 was shown to produce graphene channels with lower damage than unprocessed graphene, and also improves graphene doping bringing the Dirac point of the graphene close to 0 V. The packaging integration of microfluidics is investigated comparing traditional soft lithography approaches and the new 3D printed microfluidic approach. Specific microfluidic packaging for blood separation towards a blood sampling point of care sensor is examined to identify the laminar approach for lower blood cell count, as a method of pre-processing the blood sample before sensing.To test the sensitivity of the Post-Transfer MVD passivated graphene sensor de-veloped in this work, real-time IV measurements were performed to identify throm-bin protein binding in real-time on the graphene surface. The sensor was function-alised using a thrombin specific aptamer solution and real-time IV measurements were performed on the functionalised graphene sensor with a range of biologically relevant protein concentrations. The resulting sensitivity of the graphene sensor was in the 1-100 pg/ml concentration range, producing a resistance change of 0.2% per pg/ml. Specificity was confirmed using a non-thrombin specific aptamer as the neg-ative control. These results indicate that the graphene sensor platform developed in this thesis has the potential as a highly sensitive POCD. The processes developed here can be used to develop graphene sensors for multiple biomarkers in the future.

scholarly journals Cost-Effective Multiplex Real-Time PCR Chip System Using Open Platform Camera

2021 ◽  
Vol 6 (1) ◽  
pp. 59
Author(s):  
Sung-Hun Yun ◽  
Ji-Sung Park ◽  
Seul-Bit-Na Koo ◽  
Chan-Young Park ◽  
Yu-Seop Kim ◽  
...  
Keyword(s):  
Real Time ◽  
Printed Circuit Board ◽  
Point Of Care ◽  
Cost Effective ◽  
Reaction Chamber ◽  
Nucleic Acid Amplification ◽  
Circuit Board ◽  
Transparent Plastic ◽  
Fluorescence Response ◽  
Open Platform

This paper proposes a cost-effective real-time multiplexed polymerase chain reaction (PCR) chip system for point-of-care (POC) testing. In the proposed system, nucleic acid amplification is performed in a reaction chamber built on a printed-circuit-board (PCB) substrate with a PCB pattern heater and a thermistor. Fluorescence can be detected through the transparent plastic on the other side of the substrate. Open platform cameras were used for miniaturization and cost-effectiveness. We also used simple and cost-effective oblique lighting to stimulate fluorescence. Response performance was investigated by observing the change in the average brightness of the chamber images with various reference dye concentrations. In addition, we investigated the interference properties between different colors by measuring the fluorescence response for each dye concentration mixed with the maximum concentration of the different dyes. Quantitative performance was validated using standard DNA solutions. Experimental results show that the proposed system is suitable for POC real-time multi-PCR systems.

scholarly journals Aptamer-Based Diagnostic Systems for the Rapid Screening of TB at the Point-of-Care

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1352
Author(s):  
Darius Riziki Martin ◽  
Nicole Remaliah Sibuyi ◽  
Phumuzile Dube ◽  
Adewale Oluwaseun Fadaka ◽  
Ruben Cloete ◽  
...  
Keyword(s):  
Low Income ◽  
Point Of Care ◽  
Health Care Systems ◽  
Cost Effective ◽  
Rapid Screening ◽  
Low Income Countries ◽  
Sputum Smear ◽  
Diagnostic Systems ◽  
Molecular Tests ◽  
Rapid Tests

The transmission of Tuberculosis (TB) is very rapid and the burden it places on health care systems is felt globally. The effective management and prevention of this disease requires that it is detected early. Current TB diagnostic approaches, such as the culture, sputum smear, skin tuberculin, and molecular tests are time-consuming, and some are unaffordable for low-income countries. Rapid tests for disease biomarker detection are mostly based on immunological assays that use antibodies which are costly to produce, have low sensitivity and stability. Aptamers can replace antibodies in these diagnostic tests for the development of new rapid tests that are more cost effective; more stable at high temperatures and therefore have a better shelf life; do not have batch-to-batch variations, and thus more consistently bind to a specific target with similar or higher specificity and selectivity and are therefore more reliable. Advancements in TB research, in particular the application of proteomics to identify TB specific biomarkers, led to the identification of a number of biomarker proteins, that can be used to develop aptamer-based diagnostic assays able to screen individuals at the point-of-care (POC) more efficiently in resource-limited settings.

scholarly journals Longitudinal remotely mentored self-performed lung ultrasound surveillance of paucisymptomatic Covid-19 patients at risk of disease progression

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Andrew W. Kirkpatrick ◽  
Jessica L. McKee ◽  
John M. Conly
Keyword(s):  
At Risk ◽  
Lung Ultrasound ◽  
Point Of Care ◽  
Human Life ◽  
Vital Signs ◽  
Home Monitoring ◽  
Cost Effective ◽  
Care Providers ◽  
Vital Signs Monitoring ◽  
Ultrasound Probes

AbstractCOVID-19 has impacted human life globally and threatens to overwhelm health-care resources. Infection rates are rapidly rising almost everywhere, and new approaches are required to both prevent transmission, but to also monitor and rescue infected and at-risk patients from severe complications. Point-of-care lung ultrasound has received intense attention as a cost-effective technology that can aid early diagnosis, triage, and longitudinal follow-up of lung health. Detecting pleural abnormalities in previously healthy lungs reveal the beginning of lung inflammation eventually requiring mechanical ventilation with sensitivities superior to chest radiographs or oxygen saturation monitoring. Using a paradigm first developed for space-medicine known as Remotely Telementored Self-Performed Ultrasound (RTSPUS), motivated patients with portable smartphone support ultrasound probes can be guided completely remotely by a remote lung imaging expert to longitudinally follow the health of their own lungs. Ultrasound probes can be couriered or even delivered by drone and can be easily sterilized or dedicated to one or a commonly exposed cohort of individuals. Using medical outreach supported by remote vital signs monitoring and lung ultrasound health surveillance would allow clinicians to follow and virtually lay hands upon many at-risk paucisymptomatic patients. Our initial experiences with such patients are presented, and we believe present a paradigm for an evolution in rich home-monitoring of the many patients expected to become infected and who threaten to overwhelm resources if they must all be assessed in person by at-risk care providers.

scholarly journals Modeling Fused Filament Fabrication using Artificial Neural Networks

2021 ◽  
Author(s):  
Paul Oehlmann ◽  
Paul Osswald ◽  
Juan Camilo Blanco ◽  
Martin Friedrich ◽  
Dominik Rietzel ◽  
...  
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Cost Effective ◽  
Print Quality ◽  
Ann Model ◽  
Production Environment ◽  
Fused Filament Fabrication ◽  
Artificial Neural ◽  
Using Data ◽  
Artificial Neural Network Ann

AbstractWith industries pushing towards digitalized production, adaption to expectations and increasing requirements for modern applications, has brought additive manufacturing (AM) to the forefront of Industry 4.0. In fact, AM is a main accelerator for digital production with its possibilities in structural design, such as topology optimization, production flexibility, customization, product development, to name a few. Fused Filament Fabrication (FFF) is a widespread and practical tool for rapid prototyping that also demonstrates the importance of AM technologies through its accessibility to the general public by creating cost effective desktop solutions. An increasing integration of systems in an intelligent production environment also enables the generation of large-scale data to be used for process monitoring and process control. Deep learning as a form of artificial intelligence (AI) and more specifically, a method of machine learning (ML) is ideal for handling big data. This study uses a trained artificial neural network (ANN) model as a digital shadow to predict the force within the nozzle of an FFF printer using filament speed and nozzle temperatures as input data. After the ANN model was tested using data from a theoretical model it was implemented to predict the behavior using real-time printer data. For this purpose, an FFF printer was equipped with sensors that collect real time printer data during the printing process. The ANN model reflected the kinematics of melting and flow predicted by models currently available for various speeds of printing. The model allows for a deeper understanding of the influencing process parameters which ultimately results in the determination of the optimum combination of process speed and print quality.

scholarly journals A miniaturized optoelectronic biosensor for real-time point-of-care total protein analysis.

MethodsX ◽  
2021 ◽  
pp. 101414
Author(s):  
Ophir Vermesh ◽  
Fariah Mahzabeen ◽  
Jelena Levi ◽  
Marilyn Tan ◽  
Israt S. Alam ◽  
...  
Keyword(s):  
Real Time ◽  
Total Protein ◽  
Point Of Care ◽  
Protein Analysis ◽  
Time Point

scholarly journals 3D Printed Imaging Platform for Portable Cell Counting

The Analyst ◽  
2021 ◽  
Author(s):  
Diwakar M. Awate ◽  
Cicero C. Pola ◽  
Erica Shumaker ◽  
Carmen L Gomes ◽  
Jaime Javier Juarez
Keyword(s):  
3D Printing ◽  
Point Of Care ◽  
Cost Effective ◽  
Cell Counting ◽  
Biomedical Sciences ◽  
Widespread Application ◽  
Resource Limited ◽  
Cost Effective Approach ◽  
3D Printed

Despite having widespread application in the biomedical sciences, flow cytometers have several limitations that prevent their application to point-of-care (POC) diagnostics in resource-limited environments. 3D printing provides a cost-effective approach...

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