scholarly journals Passively Driven Microfluidic Device with Simple Operation for Quantitative Droplet LAMP Sssay for Point-of-Care Analysis

2021 ◽  
Author(s):  
Pei-Heng Lin ◽  
Bor-Ran Li
Keyword(s):  
Nucleic Acid ◽  
Point Of Care ◽  
Disease Diagnosis ◽  
Microfluidic System ◽  
Detection Methods ◽  
Heating Process ◽  
Fluid Loss ◽  
Great Opportunity ◽  
Simple Operation ◽  
Relative Standard

Abstract Since polymerase chain reaction (PCR) has become a vital tool for disease diagnosis, the development of precise applied PCR technologies in point-of care testing (POCT) has become more significant. The microfluidic-based PCR platform offers a great opportunity for on-site diagnosis efficiency, and the system is aimed at user-friendly access. Herein, we demonstrate a microfluidic system with simple operation that provides reliable nucleic acid results from 18 uniform droplets via LAMP qPCR detection. By using only micropipette regulation, users are able to control the nanoliter scale of the droplets in this valve-free and pump-free microfluidic (MF) chip. Based on the oil enclosure method and impermeable fabrication, we successfully preserved the reagent inside the microfluidic system, which significantly reduced the fluid loss and condensation. The relative standard deviation (RSD) of the fluorescence intensity between the droplets and during the heating process was <5% and 2.0%, respectively. Additionally, for different nucleic acid detection methods, the MF-LAMP chip in this study showed good applicability to both genome detection and gene expression analysis.

scholarly journals CRISPR-Based COVID-19 Testing: Toward Next-Generation Point-of-Care Diagnostics

2021 ◽  
Vol 11 ◽  
Author(s):  
Uyanga Ganbaatar ◽  
Changchun Liu
Keyword(s):  
Nucleic Acid ◽  
Point Of Care ◽  
High Sensitivity ◽  
Detection Methods ◽  
Molecular Testing ◽  
Practical Applications ◽  
Food Industries ◽  
Resource Limited ◽  
Point Of Care Diagnostics ◽  
Agriculture And Food

As the COVID-19 pandemic continues, people are becoming infected at an alarming rate, individuals are unknowingly spreading disease, and more lives are lost every day. There is an immediate need for a simple, rapid, early and sensitive point-of-care testing for COVID-19 disease. However, current testing approaches do not meet such need. Recently, clustered regularly interspaced short palindromic repeats (CRISPR)-based detection methods have received substantial attention for nucleic acid-based molecular testing due to their simplicity, high sensitivity and specificity. This review explores the various CRISPR-based COVID-19 detection methods and related diagnostic devices. As with any emerging technology, CRISPR/Cas-based nucleic acid testing methods have several challenges that must be overcome for practical applications in clinics and hospitals. More importantly, these detection methods are not limited to COVID-19 but can be applied to detect any type of pathogen, virus, and fungi that may threaten humans, agriculture, and food industries in resource-limited settings. CRISPR/Cas-based detection methods have the potential to become simpler, more reliable, more affordable, and faster in the near future, which is highly important for achieving point-of-care diagnostics.

scholarly journals Multiplexed detection of bacterial nucleic acids using Cas13 in droplet microarrays

2021 ◽  
Author(s):  
Sri Gowtham Thakku ◽  
Cheri M Ackerman ◽  
Cameron Myhrvold ◽  
Roby P Bhattacharyya ◽  
Jonathan Livny ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Sensitivity And Specificity ◽  
Health Management ◽  
Point Of Care ◽  
Bacterial Species ◽  
Bacterial Pathogen ◽  
Antibiotic Resistance Genes ◽  
Detection Methods ◽  
Nucleic Acid Detection ◽  
Multiplexed Detection

Rapid and accurate diagnosis of infections is fundamental to individual patient care and public health management. Nucleic acid detection methods are critical to this effort, but are limited either in the breadth of pathogens targeted or by the expertise and infrastructure required. We present here a high-throughput system that enables rapid identification of bacterial pathogens, bCARMEN, which utilizes: (1) modular CRISPR-Cas13-based nucleic acid detection with enhanced sensitivity and specificity; and (2) a droplet microfluidic system that enables thousands of simultaneous, spatially multiplexed detection reactions at nanoliter volumes; and (3) a novel pre-amplification strategy that further enhances sensitivity and specificity. We demonstrate bCARMEN is capable of detecting and discriminating 52 clinically relevant bacterial species and several key antibiotic resistance genes. We further develop a proof of principle system for use with stabilized reagents and a simple workflow with optical readout using a cell phone camera, opening up the possibility of a rapid point-of-care multiplexed bacterial pathogen identification and antibiotic susceptibility testing.

scholarly journals A Sensitive, Point-of-Care Detection of Small Molecules Based on a Portable Barometer: Aflatoxins In Agricultural Products

Toxins ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 158
Author(s):  
Weiqi Zhang ◽  
Wenqin Wu ◽  
Chong Cai ◽  
Xiaofeng Hu ◽  
Hui Li ◽  
...  
Keyword(s):  
Food Safety ◽  
High Performance ◽  
Large Scale ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Detection Methods ◽  
Relative Standard ◽  
Microplate Reader ◽  
Assay Precision ◽  
Point Of Care Detection

Sensitive and point-of-care detection of small toxic molecules plays a key role in food safety. Aflatoxin, a typical small toxic molecule, can cause serious healthcare and economic issues, thereby promoting the development of sensitive and point-of-care detection. Although ELISA is one of the official detection methods, it cannot fill the gap between sensitivity and point-of-care application because it requires a large-scale microplate reader. To employ portable readers in food safety, Pt-catalysis has attracted increasing attention due to its portability and reliability. In this study, we developed a sensitive point-of-care aflatoxin detection (POCAD) method via a portable handheld barometer. We synthesized and characterized Au@PtNPs and Au@PtNPs conjugated with a second antibody (Au@PtNPs-IgG). A competitive immunoassay was established based on the homemade monoclonal antibody against aflatoxins. Au@PtNPs-IgG was used to catalyze the production of O2 from H2O2 in a sealed vessel. The pressure of O2 was then recorded by a handheld barometer. The aflatoxin concentration was inversely proportional to the pressure recorded via the barometer reading. After optimization, a limit of detection of 0.03 ng/mL and a linear range from 0.09 to 16.0 ng/mL were achieved. Recovery was recorded as 83.1%–112.0% along with satisfactory results regarding inner- and inter-assay precision (relative standard deviation, RSD < 6.4%). Little cross-reaction was observed. Additionally, the POCAD was validated by high-performance liquid chromatography (HPLC) by using peanut and corn samples. The portable POCAD exhibits strong potential for applications in the on-site detection of small toxic molecules to ensure food safety.

scholarly journals A Portable Microfluidic System for Point-of-Care Detection of Multiple Protein Biomarkers

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 347
Author(s):  
Nan Li ◽  
Minjie Shen ◽  
Youchun Xu
Keyword(s):  
Point Of Care ◽  
Protein Microarray ◽  
Disease Diagnosis ◽  
Microfluidic System ◽  
Clinical Samples ◽  
Protein Biomarkers ◽  
Diagnosis And Prognosis ◽  
Multiple Protein ◽  
Commercial Instrument ◽  
Detection Of Biomarkers

Protein biomarkers are indicators of many diseases and are commonly used for disease diagnosis and prognosis prediction in the clinic. The urgent need for point-of-care (POC) detection of protein biomarkers has promoted the development of automated and fully sealed immunoassay platforms. In this study, a portable microfluidic system was established for the POC detection of multiple protein biomarkers by combining a protein microarray for a multiplex immunoassay and a microfluidic cassette for reagent storage and liquid manipulation. The entire procedure for the immunoassay was automatically conducted, which included the antibody–antigen reaction, washing and detection. Alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA) and carcinoma antigen 125 (CA125) were simultaneously detected in this system within 40 min with limits of detection of 0.303 ng/mL, 1.870 ng/mL, and 18.617 U/mL, respectively. Five clinical samples were collected and tested, and the results show good correlations compared to those measured by the commercial instrument in the hospital. The immunoassay cassette system can function as a versatile platform for the rapid and sensitive multiplexed detection of biomarkers; therefore, it has great potential for POC diagnostics.

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 Design and Manufacturing of a Disposable, Cyclo-Olefin Copolymer, Microfluidic Device for a Biosensor †

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1178 ◽  
Author(s):  
Jorge Prada ◽  
Christina Cordes ◽  
Carsten Harms ◽  
Walter Lang
Keyword(s):  
Microfluidic Device ◽  
Heating Temperature ◽  
Low Cost ◽  
Reaction Chamber ◽  
Microfluidic System ◽  
Heating Process ◽  
Design And Manufacturing ◽  
On Chip ◽  
Working Parameters ◽  
Auto Fluorescence

This contribution outlines the design and manufacturing of a microfluidic device implemented as a biosensor for retrieval and detection of bacteria RNA. The device is fully made of Cyclo-Olefin Copolymer (COC), which features low auto-fluorescence, biocompatibility and manufacturability by hot-embossing. The RNA retrieval was carried on after bacteria heat-lysis by an on-chip micro-heater, whose function was characterized at different working parameters. Carbon resistive temperature sensors were tested, characterized and printed on the biochip sealing film to monitor the heating process. Off-chip and on-chip processed RNA were hybridized with capture probes on the reaction chamber surface and identification was achieved by detection of fluorescence tags. The application of the mentioned techniques and materials proved to allow the development of low-cost, disposable albeit multi-functional microfluidic system, performing heating, temperature sensing and chemical reaction processes in the same device. By proving its effectiveness, this device contributes a reference to show the integration potential of fully thermoplastic devices in biosensor systems.

scholarly journals Rapid and Sensitive Detection of miRNA Based on AC Electrokinetic Capacitive Sensing for Point-of-Care Applications

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Clinical Diagnostics ◽  
Detection Methods ◽  
Capacitive Sensing ◽  
Application Potential ◽  
Mirna Detection ◽  
Mirna 25 ◽  
Low Sensitivity

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.

scholarly journals A glucose meter interface for point-of-care gene circuit-based diagnostics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Evan Amalfitano ◽  
Margot Karlikow ◽  
Masoud Norouzi ◽  
Katariina Jaenes ◽  
Seray Cicek ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Synthetic Biology ◽  
Molecular Diagnostics ◽  
Point Of Care ◽  
Low Cost ◽  
Gene Circuit ◽  
Reporter Systems ◽  
Glucose Meter ◽  
Pandemic Response ◽  
Glucose Output

AbstractRecent advances in cell-free synthetic biology have given rise to gene circuit-based sensors with the potential to provide decentralized and low-cost molecular diagnostics. However, it remains a challenge to deliver this sensing capacity into the hands of users in a practical manner. Here, we leverage the glucose meter, one of the most widely available point-of-care sensing devices, to serve as a universal reader for these decentralized diagnostics. We describe a molecular translator that can convert the activation of conventional gene circuit-based sensors into a glucose output that can be read by off-the-shelf glucose meters. We show the development of new glucogenic reporter systems, multiplexed reporter outputs and detection of nucleic acid targets down to the low attomolar range. Using this glucose-meter interface, we demonstrate the detection of a small-molecule analyte; sample-to-result diagnostics for typhoid, paratyphoid A/B; and show the potential for pandemic response with nucleic acid sensors for SARS-CoV-2.

scholarly journals Optical-Based Biosensors and Their Portable Healthcare Devices for Detecting and Monitoring Biomarkers in Body Fluids

Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1285
Author(s):  
Anh Tran Tam Pham ◽  
Angus Wallace ◽  
Xinyi Zhang ◽  
Damian Tohl ◽  
Hao Fu ◽  
...  
Keyword(s):  
Medical Devices ◽  
Point Of Care ◽  
Body Fluids ◽  
Optical Measurements ◽  
Mobile Technologies ◽  
Detection Methods ◽  
Portable Devices ◽  
Bodily Fluids ◽  
Clinical Measurements ◽  
Distinct Features

The detection and monitoring of biomarkers in body fluids has been used to improve human healthcare activities for decades. In recent years, researchers have focused their attention on applying the point-of-care (POC) strategies into biomarker detection. The evolution of mobile technologies has allowed researchers to develop numerous portable medical devices that aim to deliver comparable results to clinical measurements. Among these, optical-based detection methods have been considered as one of the common and efficient ways to detect and monitor the presence of biomarkers in bodily fluids, and emerging aggregation-induced emission luminogens (AIEgens) with their distinct features are merging with portable medical devices. In this review, the detection methodologies that use optical measurements in the POC systems for the detection and monitoring of biomarkers in bodily fluids are compared, including colorimetry, fluorescence and chemiluminescence measurements. The current portable technologies, with or without the use of smartphones in device development, that are combined with optical biosensors for the detection and monitoring of biomarkers in body fluids, are also investigated. The review also discusses novel AIEgens used in the portable systems for the detection and monitoring of biomarkers in body fluid. Finally, the potential of future developments and the use of optical detection-based portable devices in healthcare activities are explored.

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