scholarly journals Reducing Unspecific Protein Adsorption in Microfluidic Papers Using Fiber-Attached Polymer Hydrogels

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6348
Author(s):  
Alexander Ritter von Stockert ◽  
Anna Luongo ◽  
Markus Langhans ◽  
Thomas Brandstetter ◽  
Jürgen Rühe ◽  
...  
Keyword(s):  
Protein Transport ◽  
Point Of Care ◽  
Low Cost ◽  
Local Heating ◽  
Free Water ◽  
Lateral Flow ◽  
Paper Strip ◽  
Detection Zone ◽  
Free Paper ◽  
Lateral Flow Assays

Microfluidic paper combines pump-free water transport at low cost with a high degree of sustainability, as well as good availability of the paper-forming cellulosic material, thus making it an attractive candidate for point-of-care (POC) analytics and diagnostics. Although a number of interesting demonstrators for such paper devices have been reported to date, a number of challenges still exist, which limit a successful transfer into marketable applications. A strong limitation in this respect is the (unspecific) adsorption of protein analytes to the paper fibers during the lateral flow assay. This interaction may significantly reduce the amount of analyte that reaches the detection zone of the microfluidic paper-based analytical device (µPAD), thereby reducing its overall sensitivity. Here, we introduce a novel approach on reducing the nonspecific adsorption of proteins to lab-made paper sheets for the use in µPADs. To this, cotton linter fibers in lab-formed additive-free paper sheets are modified with a surrounding thin hydrogel layer generated from photo-crosslinked, benzophenone functionalized copolymers based on poly-(oligo-ethylene glycol methacrylate) (POEGMA) and poly-dimethyl acrylamide (PDMAA). This, as we show in tests similar to lateral flow assays, significantly reduces unspecific binding of model proteins. Furthermore, by evaporating the transport fluid during the microfluidic run at the end of the paper strip through local heating, model proteins can almost quantitatively be accumulated in that zone. The possibility of complete, almost quantitative protein transport in a µPAD opens up new opportunities to significantly improve the signal-to-noise (S/N) ratio of paper-based lateral flow assays.

scholarly journals Integrating high-performing electrochemical transducers in lateral flow assay

2021 ◽  
Author(s):  
Antonia Perju ◽  
Nongnoot Wongkaew
Keyword(s):  
High Performance ◽  
Point Of Care ◽  
Low Cost ◽  
High Sensitivity ◽  
Lateral Flow ◽  
Analytical Performance ◽  
Label Free ◽  
High Performing ◽  
Lateral Flow Assays ◽  
Electrochemical Transducers

AbstractLateral flow assays (LFAs) are the best-performing and best-known point-of-care tests worldwide. Over the last decade, they have experienced an increasing interest by researchers towards improving their analytical performance while maintaining their robust assay platform. Commercially, visual and optical detection strategies dominate, but it is especially the research on integrating electrochemical (EC) approaches that may have a chance to significantly improve an LFA’s performance that is needed in order to detect analytes reliably at lower concentrations than currently possible. In fact, EC-LFAs offer advantages in terms of quantitative determination, low-cost, high sensitivity, and even simple, label-free strategies. Here, the various configurations of EC-LFAs published are summarized and critically evaluated. In short, most of them rely on applying conventional transducers, e.g., screen-printed electrode, to ensure reliability of the assay, and additional advances are afforded by the beneficial features of nanomaterials. It is predicted that these will be further implemented in EC-LFAs as high-performance transducers. Considering the low cost of point-of-care devices, it becomes even more important to also identify strategies that efficiently integrate nanomaterials into EC-LFAs in a high-throughput manner while maintaining their favorable analytical performance.

scholarly journals Electrospun Polycaprolactone Nanofibers as a Reaction Membrane for Lateral Flow Assay

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1387 ◽  
Author(s):  
Chee Yew ◽  
Pedram Azari ◽  
Jane Choi ◽  
Farina Muhamad ◽  
Belinda Pingguan-Murphy
Keyword(s):  
Flow Rate ◽  
Point Of Care ◽  
Low Cost ◽  
Average Pore Size ◽  
Lateral Flow ◽  
Detection Sensitivity ◽  
Average Pore ◽  
Water Contact ◽  
Naoh Solution ◽  
Lateral Flow Assays

Electrospun polycaprolactone (PCL) nanofibers have emerged as a promising material in diverse biomedical applications due to their various favorable features. However, their application in the field of biosensors such as point-of-care lateral flow assays (LFA) has not been investigated. The present study demonstrates the use of electrospun PCL nanofibers as a reaction membrane for LFA. Electrospun PCL nanofibers were treated with NaOH solution for different concentrations and durations to achieve a desirable flow rate and optimum detection sensitivity in nucleic acid-based LFA. It was observed that the concentration of NaOH does not affect the physical properties of nanofibers, including average fiber diameter, average pore size and porosity. However, interestingly, a significant reduction of the water contact angle was observed due to the generation of hydroxyl and carboxyl groups on the nanofibers, which increased their hydrophilicity. The optimally treated nanofibers were able to detect synthetic Zika viral DNA (as a model analyte) sensitively with a detection limit of 0.5 nM. Collectively, the benefits such as low-cost of fabrication, ease of modification, porous nanofibrous structures and tunability of flow rate make PCL nanofibers a versatile alternative to nitrocellulose membrane in LFA applications. This material offers tremendous potential for a broad range of point-of-care applications.

scholarly journals Engineering luminescent biosensors for point-of-care SARS-CoV-2 antibody detection

2020 ◽  
Author(s):  
Susanna K. Elledge ◽  
Xin X. Zhou ◽  
James R. Byrnes ◽  
Alexander J. Martinko ◽  
Irene Lui ◽  
...  
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Low Cost ◽  
Lateral Flow ◽  
Antibody Detection ◽  
Lateral Flow Assays ◽  
Quantitative Results ◽  
Development And Validation ◽  
Antibody Tests ◽  
Split Luciferase

Current serology tests for SARS-CoV-2 antibodies mainly take the form of enzyme-linked immunosorbent assays or lateral flow assays, with the former being laborious and the latter being expensive and often lacking sufficient sensitivity and scalability. Here we present the development and validation of a rapid, low-cost solution-based assay to detect antibodies in serum, plasma, whole blood, and saliva, using rationally designed split luciferase antibody biosensors (spLUC). This new assay, which generates quantitative results in as short as 5 minutes, substantially reduces the complexity and improves the scalability of COVID-19 antibody tests for point-of-care and broad population testing.

Lateral flow assay with pressure meter readout for rapid point-of-care detection of disease-associated protein

Lab on a Chip ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 965-970 ◽  
Author(s):  
Bingqian Lin ◽  
Zhichao Guan ◽  
Yanling Song ◽  
Eunyeong Song ◽  
Zifei Lu ◽  
...  
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Lateral Flow Assays ◽  
Pressure Meter ◽  
User Friendly ◽  
Point Of Care Detection

Paper-based assays such as lateral flow assays are good candidates for portable diagnostics owing to their user-friendly format and low cost.

Gold-Aptamer-Nanoconstructs Engineered to Detect Conserved Enteroviral Nucleic Acid Sequences

2019 ◽  
Author(s):  
Veeren Chauhan ◽  
Mohamed M Elsutohy ◽  
C Patrick McClure ◽  
Will Irving ◽  
Neil Roddis ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
In Silico ◽  
Point Of Care ◽  
Lateral Flow ◽  
Nucleic Acid Sequence ◽  
In Silico Screening ◽  
Lateral Flow Assays ◽  
Life Threatening ◽  
Software And Hardware ◽  
Nucleic Acid Sequences

<p>Enteroviruses are a ubiquitous mammalian pathogen that can produce mild to life-threatening disease. Bearing this in mind, we have developed a rapid, accurate and economical point-of-care biosensor that can detect a nucleic acid sequences conserved amongst 96% of all known enteroviruses. The biosensor harnesses the physicochemical properties of gold nanoparticles and aptamers to provide colourimetric, spectroscopic and lateral flow-based identification of an exclusive enteroviral RNA sequence (23 bases), which was identified through in silico screening. Aptamers were designed to demonstrate specific complementarity towards the target enteroviral RNA to produce aggregated gold-aptamer nanoconstructs. Conserved target enteroviral nucleic acid sequence (≥ 1x10<sup>-7</sup> M, ≥1.4×10<sup>-14</sup> g/mL), initiates gold-aptamer-nanoconstructs disaggregation and a signal transduction mechanism, producing a colourimetric and spectroscopic blueshift (544 nm (purple) > 524 nm (red)). Furthermore, lateral-flow-assays that utilise gold-aptamer-nanoconstructs were unaffected by contaminating human genomic DNA, demonstrated rapid detection of conserved target enteroviral nucleic acid sequence (< 60 s) and could be interpreted with a bespoke software and hardware electronic interface. We anticipate our methodology will translate in-silico screening of nucleic acid databases to a tangible enteroviral desktop detector, which could be readily translated to related organisms. This will pave-the-way forward in the clinical evaluation of disease and complement existing strategies at overcoming antimicrobial resistance.</p>

scholarly journals Oligonucleotide-templated lateral flow assays for amplification-free sensing of circulating microRNAs

2019 ◽  
Vol 55 (83) ◽  
pp. 12451-12454 ◽  
Author(s):  
Suraj Pavagada ◽  
Robert B. Channon ◽  
Jason Y. H. Chang ◽  
Sung Hye Kim ◽  
David MacIntyre ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Minimally Invasive ◽  
Low Cost ◽  
Maternal Blood ◽  
Lateral Flow ◽  
Early Prediction ◽  
Circulating Micrornas ◽  
Lateral Flow Assays

Low-cost detection of miRNA biomarkers from maternal blood is achieved via a highly sequence-specific templated reaction on nitrocellulose paper strips to enable early prediction of preterm birth in a minimally invasive manner.

Development of a Smartphone Based Reader for the Quantitative Analysis of Lateral Flow Assays

2018 ◽  
Vol 941 ◽  
pp. 2522-2527
Author(s):  
Sylvio Schneider ◽  
Martina Selig ◽  
Verena Keil ◽  
Matthias Lehmann ◽  
Andreas H. Foitzik ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Medical Devices ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Thrombotic Event ◽  
Lateral Flow ◽  
Proof Of Concept ◽  
Lateral Flow Assays ◽  
Further Development ◽  
D Dimer

Smartphones are developing into all-purposes devices. In the present work, the employment/application of smartphones as medical devices in home care and point-of-care (POC) diagnostics are investigated in the analysis of Lateral Flow Assays (LFA). A smartphone-based LFA reader was developed for the quantitative analysis of D-Dimer – a biomarker indicating e.g. thrombotic event or danger of embolism.The proof-of-concept has been shown with multiple smartphones in establishing: (I) Optimal dimensions of the LFA cell of 72.11mm distance of smartphone to D-Dimer test leading to a coefficients of variances (CV) between 0.8% and 4.2%. (II) Inter-device investigations: CVs around 13.5%; a limit of detection (LOD) of 100ng/ml (DDU) D-Dimer. (III) Inter-smartphone investigations: CV about 16%, a limit of detection (LOD) at 66.4ng/ml (DDU). (IV) Calibrations: CV and LOD of three smartphones are comparable to the commercial available LFA reader. Further development to put the multiple smartphone-based LFA reader on the market.

scholarly journals Open-source, Adaptable, All-in-one Smartphone-based System for Quantitative Analysis of Point-of-care Diagnostics.

2021 ◽  
Author(s):  
Weronika Schary ◽  
Filip Paskali ◽  
Simone Rentschler ◽  
Christoph Ruppert ◽  
Gabriel Wagner ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Open Source ◽  
Low Income ◽  
Point Of Care ◽  
Low Cost ◽  
Data Extraction ◽  
Diagnostic Testing ◽  
Analysis Data ◽  
Great Opportunity ◽  
Lateral Flow Assays

Abstract Point-of-care (POC) diagnostics, in particular lateral flow assays (LFA), represent a great opportunity for rapid, precise, low-cost and accessible diagnosis of disease. Especially with the ongoing coronavirus disease 2019 (COVID-19) pandemic, rapid point-of-care tests are becoming everyday tools for identification and prevention. Using smartphones as biosensors can enhance POC devices as portable, low-cost POC platforms for healthcare and medicine, food and environmental monitoring, improving diagnosis and documentation in remote, low-income locations. We present an open-source, all-in-one smartphone-based system for quantitative analysis of LFAs. It consists of a 3D-printed photo box, a smartphone for image acquisition, and an R Shiny software package with modular, customizable analysis workflow for image editing, analysis, data extraction, calibration and quantification of the assays. This system is less expensive than commonly used hardware and software, so it could prove very beneficial for diagnostic testing in the context of pandemics, as well as in low-resource countries.

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