1,163 results match your criteria microfluidics biosensing

One-step enzyme kinetics measurement in 3D printed microfluidics devices based on a high-performance single vibrating sharp-tip mixer.

Anal Chim Acta 2021 Aug 24;1172:338677. Epub 2021 May 24.

C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA. Electronic address:

Measuring enzyme kinetics is of great importance to understand many biological processes and improve biosensing and industrial applications. Conventional methods of measuring enzyme kinetics require to prepare a series of solutions with different substrate concentrations and measure the signal response over time with these solutions, leading to tedious sample preparation steps, high reagents/sample consumption, and difficulties in studying fast enzyme kinetics. Here we report a one-step assay to measure enzyme kinetics using a 3D-printed microfluidic device, which eliminates the steps of preparing and handling multiple solutions thereby simplifying the whole workflow significantly. Read More

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Mixing during Trapping Enabled a Continuous-Flow Microfluidic Smartphone Immunoassay Using Acoustic Streaming.

ACS Sens 2021 Jun 8. Epub 2021 Jun 8.

State Key Laboratory of Precision Measuring Technology & Instruments and College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin 300072, China.

Smartphone-enabled microfluidic chemiluminescence immunoassay is a promising portable system for point-of-care (POC) biosensing applications. However, due to the rather faint emitted light in such a limited sample volume, it is still difficult to reach the clinically accepted range when the smartphone serves as a standalone detector. Besides, the multiple separation and washing steps during sample preparation hinder the immunoassay's applications for POC usage. Read More

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Microfluidic circulating reactor system for sensitive and automated duplex-specific nuclease-mediated microRNA detection.

Talanta 2021 Sep 20;232:122396. Epub 2021 Apr 20.

Department of Chemistry, University of Florida, Gainesville, FL, 32611, USA; University of Florida Health Cancer Center, Gainesville, FL, 32610, USA. Electronic address:

Duplex-specific nuclease signal amplification (DSNSA) is a promising microRNA (miRNA) quantification strategy. However, existing DSNSA based miRNA detection methods suffer from costly chemical consumptions and require laborious multi-step sample pretreatment that are prone to sample loss and contamination, including total RNA extraction and enrichment. To address these problems, herein we devised a pneumatically automated microfluidic reactor device that integrates both analyte extraction/enrichment and DSNSA-mediated miRNA detection in one streamlined analysis workflow. Read More

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September 2021

Analysis of Temperature-Jump Boundary Conditions on Heat Transfer for Heterogeneous Microfluidic Immunosensors.

Sensors (Basel) 2021 May 18;21(10). Epub 2021 May 18.

Electronic and Microelectronics Lab, Department of Physics, Faculty of Science of Monastir, University of Monastir, Monastir 5019, Tunisia.

The objective of the current study is to analyze numerically the effect of the temperature-jump boundary condition on heterogeneous microfluidic immunosensors under electrothermal force. A three-dimensional simulation using the finite element method on the binding reaction kinetics of C-reactive protein (CRP) was performed. The kinetic reaction rate was calculated with coupled Laplace, Navier-Stokes, energy, and mass diffusion equations. Read More

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A Self-Priming Microfluidic Chip with Cushion Chambers for Easy Digital PCR.

Biosensors (Basel) 2021 May 18;11(5). Epub 2021 May 18.

State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China.

A polydimethylsiloxane (PDMS)-based self-priming microfluidic chip with cushion chambers is presented in this study for robust and easy-operation digital polymerase chain reaction (dPCR). The chip has only one inlet and can partition samples autonomously through negative pressure, provided by a de-gassed PDMS layer with a multi-level vertical branching microchannel design. Meanwhile, cushion chambers make the chip capable of very robust use for sample partitioning. Read More

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Imaging-based spectrometer-less optofluidic biosensors based on dielectric metasurfaces for detecting extracellular vesicles.

Nat Commun 2021 05 31;12(1):3246. Epub 2021 May 31.

Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.

Biosensors are indispensable tools for public, global, and personalized healthcare as they provide tests that can be used from early disease detection and treatment monitoring to preventing pandemics. We introduce single-wavelength imaging biosensors capable of reconstructing spectral shift information induced by biomarkers dynamically using an advanced data processing technique based on an optimal linear estimator. Our method achieves superior sensitivity without wavelength scanning or spectroscopy instruments. Read More

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Cellular lensing and near infrared fluorescent nanosensor arrays to enable chemical efflux cytometry.

Nat Commun 2021 05 25;12(1):3079. Epub 2021 May 25.

Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.

Nanosensors have proven to be powerful tools to monitor single cells, achieving spatiotemporal precision even at molecular level. However, there has not been way of extending this approach to statistically relevant numbers of living cells. Herein, we design and fabricate nanosensor array in microfluidics that addresses this limitation, creating a Nanosensor Chemical Cytometry (NCC). Read More

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Human sensor-inspired supervised machine learning of smartphone-based paper microfluidic analysis for bacterial species classification.

Biosens Bioelectron 2021 Sep 14;188:113335. Epub 2021 May 14.

Department of Biosystems Engineering, The University of Arizona, Tucson, AZ, 85721, United States; Department of Biomedical Engineering, The University of Arizona, Tucson, AZ, 85721, United States. Electronic address:

Bacteria identification has predominantly been conducted using specific bioreceptors such as antibodies or nucleic acid sequences. This approach may be inappropriate for environmental monitoring when the user does not know the target bacterial species and for screening complex water samples with many unknown bacterial species. In this work, we investigate the supervised machine learning of the bacteria-particle aggregation pattern induced by the peptide sets identified from the biofilm-bacteria interface. Read More

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September 2021

Label-free terahertz microfluidic biosensor for sensitive DNA detection using graphene-metasurface hybrid structures.

Biosens Bioelectron 2021 Sep 14;188:113336. Epub 2021 May 14.

College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Rd., 310058, Hangzhou, Zhejiang Province, PR China.

Metasurface assisted terahertz (THz) real-time and label-free biosensors have attracted intense attention. However, it is still challenging for specific detection of highly absorptive liquid samples with high sensitivity in the THz range. Here, we incorporated graphene with THz metasurface into a microfluidic cell for sensitive biosensing. Read More

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September 2021

Emerging methods in biomarker identification for extracellular vesicle-based liquid biopsy.

J Extracell Vesicles 2021 May 12;10(7):e12090. Epub 2021 May 12.

Department Biomedical Engineering Carnegie Mellon University Pittsburgh Pennsylvania USA.

Extracellular vesicles (EVs) are released by many cell types and distributed within various biofluids. EVs have a lipid membrane-confined structure that allows for carrying unique molecular information originating from their parent cells. The species and quantity of EV cargo molecules, including nucleic acids, proteins, lipids, and metabolites, may vary largely owing to their parent cell types and the pathophysiologic status. Read More

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A microfluidic microparticle-labeled impedance sensor array for enhancing immunoassay sensitivity.

Analyst 2021 May 14;146(10):3289-3298. Epub 2021 Apr 14.

Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, USA.

An impedimetric biosensor is used to measure electrical impedance changes in the presence of biomolecules from sinusoidal input voltages. In this paper, we present a new portable impedance-based biosensor platform to improve the sensitivity of immunoassays with microparticles as a label. Using a 2 × 4 interdigitated electrode array with a 10/10 μm electrode/gap and a miniaturized impedance analyzer, we performed immunoassays with microparticles by integrating a microfluidic channel to evaluate signal enhancement. Read More

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Synergizing Functional Nanomaterials with Aptamers Based on Electrochemical Strategies for Pesticide Detection: Current Status and Perspectives.

Crit Rev Anal Chem 2021 May 12:1-28. Epub 2021 May 12.

Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.

Owing to the high toxicity and large-scale use of pesticides, it is imperative to develop selective, sensitive, portable, and convenient sensors for rapid monitoring of pesticide. Therefore, the electrochemical detection platform offers a promising analytical approach since it is easy to operate, economical, efficient, and user-friendly. Meanwhile, with advances in functional nanomaterials and aptamer selection technologies, numerous sensitivity-enhancement techniques alongside a widespread range of smart nanomaterials have been merged to construct novel aptamer probes to use in the biosensing field. Read More

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Optically Driven Gold Nanoparticles Seed Surface Bubble Nucleation in Plasmonic Suspension.

Nano Lett 2021 May 3. Epub 2021 May 3.

Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States.

Photothermal surface bubbles play important roles in applications like microfluidics and biosensing, but their formation on transparent substrates immersed in a plasmonic nanoparticle (NP) suspension has an unknown origin. Here, we reveal NPs deposited on the transparent substrate by optical forces are responsible for the nucleation of such photothermal surface bubbles. We show the surface bubble formation is always preceded by the optically driven NPs moving toward and deposited to the surface. Read More

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A rotationally focused flow (RFF) microfluidic biosensor by density difference for early-stage detectable diagnosis.

Sci Rep 2021 04 29;11(1):9277. Epub 2021 Apr 29.

School of Mechanical and Aerospace Engineering, Nanyang Technological University (NTU), Singapore, 639798, Singapore.

Label-free optical biosensors have received tremendous attention in point-of-care testing, especially in the emerging pandemic, COVID-19, since they advance toward early-detection, rapid, real-time, ease-of-use, and low-cost paradigms. Protein biomarkers testings require less sample modification process compared to nucleic-acid biomarkers'. However, challenges always are in detecting low-concentration for early-stage diagnosis. Read More

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Paper-Based Biosensors: Frontiers in Point-of-Care Detection of COVID-19 Disease.

Biosensors (Basel) 2021 Apr 7;11(4). Epub 2021 Apr 7.

Department of Chemistry and Drug Technologies, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.

This review summarizes the state of the art of paper-based biosensors (PBBs) for coronavirus disease 2019 (COVID-19) detection. Three categories of PBB are currently being been used for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostics, namely for viral gene, viral antigen and antibody detection. The characteristics, the analytical performance, the advantages and drawbacks of each type of biosensor are highlighted and compared with traditional methods. Read More

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Ultra-high-frequency (UHF) surface-acoustic-wave (SAW) microfluidics and biosensors.

Nanotechnology 2021 May 10;32(31). Epub 2021 May 10.

INTA srl, Intelligent Acoustics Systems, Via Nino Pisano 14, I-56122 Pisa, Italy.

Surface acoustic waves (SAWs) have the potential to become the basis for a wide gamut of lab-on-a-chips (LoCs). These mechanical waves are among the most promising physics that can be exploited for fulfilling all the requirements of commercially appealing devices that aim to replace-or help-laboratory facilities. These requirements are low processing cost of the devices, scalable production, controllable physics, large flexibility of tasks to perform, easy device miniaturization. Read More

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Selective target protein detection using a decorated nanopore into a microfluidic device.

Biosens Bioelectron 2021 Jul 31;183:113195. Epub 2021 Mar 31.

Université Paris-Saclay, Univ Evry, CNRS, LAMBE, 91025, Evry-Courcouronnes, France. Electronic address:

Solid-state nanopores provide a powerful tool to electrically analyze nanoparticles and biomolecules at single-molecule resolution. These biosensors need to have a controlled surface to provide information about the analyte. Specific detection remains limited due to nonspecific interactions between the molecules and the nanopore. Read More

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Islet-on-a-chip: Biomimetic micropillar-based microfluidic system for three-dimensional pancreatic islet cell culture.

Biosens Bioelectron 2021 Jul 2;183:113215. Epub 2021 Apr 2.

Medical Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Poland. Electronic address:

Type 2 diabetes is currently one of the most common metabolic diseases, affecting all ages worldwide. As the incidence of type 2 diabetes increases, a growing number of studies focus on islets of Langerhans. A three-dimensional research model that maps islet morphology and maintains hormonal balance in vivo is still needed. Read More

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Emerging technologies and commercial products in exosome-based cancer diagnosis and prognosis.

Biosens Bioelectron 2021 Jul 27;183:113176. Epub 2021 Mar 27.

BioMEMS and Bioinspired Microfluidic Laboratory, Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta T2N 1N4, Canada; Center for Bioengineering Research and Education, University of Calgary, Calgary, Alberta T2N 1N4, Canada. Electronic address:

Academic and industrial groups worldwide have reported technological advances in exosome-based cancer diagnosis and prognosis. However, the potential translation of these emerging technologies for research and clinical settings remains unknown. This work overviews the role of exosomes in cancer diagnosis and prognosis, followed by a survey on emerging exosome technologies, particularly microfluidic advances for the isolation and detection of exosomes in cancer research. Read More

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Development of a multiparametric (bio)sensing platform for continuous monitoring of stress metabolites.

Talanta 2021 Jul 15;229:122275. Epub 2021 Mar 15.

Univ. Grenoble Alpes, CEA, LETI, DTBS, L2CB, 38000, Grenoble, France. Electronic address:

There is a growing need for real-time monitoring of metabolic products that could reflect cell damages over extended periods. In this paper, we report the design and development of an original multiparametric (bio)sensing platform that is tailored for the real-time monitoring of cell metabolites derived from cell cultures. Most attractive features of our developed electrochemical (bio)sensing platform are its easy manufacturing process, that enables seamless scale-up, modular and versatile approach, and low cost. Read More

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Nondestructive multiplex detection of foodborne pathogens with background microflora and symbiosis using a paper chromogenic array and advanced neural network.

Biosens Bioelectron 2021 Jul 1;183:113209. Epub 2021 Apr 1.

Department of Biomedical and Nutritional Sciences, University of Massachusetts, Lowell, 01854, MA, USA. Electronic address:

We have developed an inexpensive, standardized paper chromogenic array (PCA) integrated with a machine learning approach to accurately identify single pathogens (Listeria monocytogenes, Salmonella Enteritidis, or Escherichia coli O157:H7) or multiple pathogens (either in multiple monocultures, or in a single cocktail culture), in the presence of background microflora on food. Cantaloupe, a commodity with significant volatile organic compound (VOC) emission and large diverse populations of background microflora, was used as the model food. The PCA was fabricated from a paper microarray via photolithography and paper microfluidics, into which 22 chromogenic dye spots were infused and to which three red/green/blue color-standard dots were taped. Read More

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A Miniature Bio-Photonics Companion Diagnostics Platform for Reliable Cancer Treatment Monitoring in Blood Fluids.

Sensors (Basel) 2021 Mar 23;21(6). Epub 2021 Mar 23.

Institute of Communication and Computer Systems (ICCS), National Technical University of Athens, Heroon Polytehneiou 9, 15780 Athens, Greece.

In this paper, we present the development of a photonic biosensor device for cancer treatment monitoring as a complementary diagnostics tool. The proposed device combines multidisciplinary concepts from the photonic, nano-biochemical, micro-fluidic and reader/packaging platforms aiming to overcome limitations related to detection reliability, sensitivity, specificity, compactness and cost issues. The photonic sensor is based on an array of six asymmetric Mach Zender Interferometer (aMZI) waveguides on silicon nitride substrates and the sensing is performed by measuring the phase shift of the output signal, caused by the binding of the analyte on the functionalized aMZI surface. Read More

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Microfluidic Impedance Biosensor Chips Using Sensing Layers Based on DNA-Based Self-Assembled Monolayers for Label-Free Detection of Proteins.

Biosensors (Basel) 2021 Mar 13;11(3). Epub 2021 Mar 13.

Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.

A microfluidic chip for electrochemical impedance spectroscopy (EIS) is presented as bio-sensor for label-free detection of proteins by using the example of cardiac troponin I. Troponin I is one of the most specific diagnostic serum biomarkers for myocardial infarction. The microfluidic impedance biosensor chip presented here consists of a microscope glass slide serving as base plate, sputtered electrodes, and a polydimethylsiloxane (PDMS) microchannel. Read More

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3D-PAD: Paper-Based Analytical Devices with Integrated Three-Dimensional Features.

Biosensors (Basel) 2021 Mar 17;11(3). Epub 2021 Mar 17.

Pillar of Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore.

This paper describes the use of fused deposition modeling (FDM) printing to fabricate paper-based analytical devices (PAD) with three-dimensional (3D) features, which is termed as 3D-PAD. Material depositions followed by heat reflow is a standard approach for the fabrication of PAD. Such devices are primarily two-dimensional (2D) and can hold only a limited amount of liquid samples in the device. Read More

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Microfluidic thread-based electrochemical aptasensor for rapid detection of Vibrio parahaemolyticus.

Biosens Bioelectron 2021 Jun 24;182:113191. Epub 2021 Mar 24.

School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611731, China. Electronic address:

Vibrio parahaemolyticus is one of the foodborne bacteria that widely present in seafood as well as the leading cause of seafood-associated bacterial gastroenteritis. Traditional identification of such pathogens mainly relies on culturing methods, ELISA or PCR. These methods are usually laborious, time-consuming with poor diagnosis competences, or require costly and bulky equipment though of high sensitivity. Read More

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Pushbutton-activated microfluidic dropenser for droplet digital PCR.

Biosens Bioelectron 2021 Jun 13;181:113159. Epub 2021 Mar 13.

Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea. Electronic address:

Here, we report a portable microfluidic device to generate and dispense droplets simply operated by pushbutton for droplet digital polymerase chain reaction (ddPCR), which is named pushbutton-activated microfluidic dropenser (droplet dispenser) (PAMD). After loading the PCR mixtures and the droplet generation oil to PAMD, digitized PCR mixtures are prepared in PCR tubes after the actuation of a pushbutton. Multiple droplet generation units are simultaneously operated by a single pushbutton, and the size of droplets is controllable by adjusting the geometry of the droplet generation channel. Read More

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High-throughput human DNA purification on a centrifugal microfluidic device for rapid forensic sex-typing.

Biosens Bioelectron 2021 Jun 13;181:113161. Epub 2021 Mar 13.

Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin, 17104, South Korea. Electronic address:

We introduce a novel centrifugal disc for purifying nucleic acid (NA) in a high-throughput manner to perform the human sex-typing of forensic samples. The centrifugal disc was designed with double-sided etched channels to fabricate 30 extraction units, which was capable of purifying 30 forensic samples in a single run. In order to introduce the washing solution (70% ethanol) and the elution buffer for the 30 extraction units in an automatic manner, we designed the aliquoting chambers that were connected with a zigzag delivery channel. Read More

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Gut-on-a-chip: Mimicking and monitoring the human intestine.

Biosens Bioelectron 2021 Jun 8;181:113156. Epub 2021 Mar 8.

Instituto de Microelectrónica de Barcelona (IMB-CNM, CSIC), Campus UAB, Bellaterra, 08193, Barcelona, Spain; Centro de Investigación Biomédica en Red en Bioingeniería Biomateriales y Nanomedicina (CIBER-BBN), Madrid, 50018, Spain. Electronic address:

Over the last few years, the intestine has been extensively studied using in vitro microfluidic systems, commonly known as gut-on-a-chip (GOC) devices. This interest has been due not only to the importance of the intestine's proper functions but also to the relationship that this organ and the microbiota that inhabits it has with the rest of the body's organs. The increased complexity of these in vitro systems, together with the need to improve our understanding of intestinal physiology interdependencies, has led to greater focus on the integration of biosensors within these devices. Read More

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A wearable patch for continuous analysis of thermoregulatory sweat at rest.

Nat Commun 2021 03 23;12(1):1823. Epub 2021 Mar 23.

Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA, USA.

The body naturally and continuously secretes sweat for thermoregulation during sedentary and routine activities at rates that can reflect underlying health conditions, including nerve damage, autonomic and metabolic disorders, and chronic stress. However, low secretion rates and evaporation pose challenges for collecting resting thermoregulatory sweat for non-invasive analysis of body physiology. Here we present wearable patches for continuous sweat monitoring at rest, using microfluidics to combat evaporation and enable selective monitoring of secretion rate. Read More

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A pocket-sized device automates multiplexed point-of-care RNA testing for rapid screening of infectious pathogens.

Biosens Bioelectron 2021 Jun 10;181:113145. Epub 2021 Mar 10.

Department of Laboratory Medicine, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, 510180, China; Department of Laboratory Medicine, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, 510180, China; Clinical Molecular Medicine and Molecular Diagnosis Key Laboratory of Guangdong Province, Guangzhou, 510180, China; Guangdong Engineering Technology Research Center of Microfluidic Chip Medical Diagnosis, Guangzhou, 510180, China. Electronic address:

Rapid screening of infectious pathogens at the point-of-care (POC) is ideally low-cost, portable, easy to use, and capable of multiplex detection with high sensitivity. However, satisfying all these features in a single device without compromise remains a challenging task. Here, we introduce an ultraportable, automated RNA amplification testing device that allows rapid screening of infectious pathogens from clinical samples. Read More

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