Development of Ball-Enabled Miniaturized Valves for Sample Preparation and Microheaters for Pathogen Detection

2020 ◽  
Author(s):  
Carlos Manzanas ◽  
Xiao Jiang ◽  
John A. Lednicky ◽  
Z. Hugh Fan
Keyword(s):  
Zika Virus ◽  
Pathogen Detection ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Public Health Problem ◽  
Cost Effective ◽  
Nucleic Acid Amplification ◽  
Rna Amplification ◽  
Testing Platform ◽  
The Past

Abstract There have been numerous Zika virus (ZIKV) outbreaks in the past few years, representing a public health problem. The recommended tests for the diagnosis of Zika infections are performed in a laboratory setting. However, diagnostics platforms at the point-of-care (POC) are highly desirable for understanding and preventing ZIKV transmission. To address this need, we have developed a testing platform that (1) can be operated in the field for pathogen detection, (2) is rapid, cost-effective, and reliable, and (3) does not require a power supply. To realize the platform, we have developed (1) a series of ball-based valves for the storage and sequential delivery of reagents and (2) microheater-enabled RNA amplification, both of which are integral components of this POC device. The multiple reagents are needed for virus lysis, RNA enrichment and purification. These ball-based are employed for fluid-control and they are actuated manually by sliding the unit and a pole under it, which can lift the balls. Nucleic acid amplification is then performed by a smart coffee mug that provides a constant temperature for reverse transcription loop mediated isothermal amplification (RT-LAMP), followed by colorimetric detection. We have demonstrated the detection of Zika virus in human urine and saliva samples using this testing platform.

scholarly journals Context-Specific Procedures for the Diagnosis of Human Schistosomiasis – A Mini Review

2021 ◽  
Vol 2 ◽  
Author(s):  
Pytsje T. Hoekstra ◽  
Govert J. van Dam ◽  
Lisette van Lieshout
Keyword(s):  
Diagnostic Tests ◽  
Point Of Care ◽  
Public Health Problem ◽  
Nucleic Acid Amplification ◽  
Antibody Detection ◽  
Infection Model ◽  
Related Factors ◽  
Human Schistosomiasis ◽  
Diagnostic Approaches ◽  
Context Specific

Schistosomiasis is a parasitic disease caused by trematode blood flukes of the genus Schistosoma, affecting over 250 million people mainly in the tropics. Clinically, the disease can present itself with acute symptoms, a stage which is relatively more common in naive travellers originating from non-endemic regions. It can also develop into chronic disease, with the outcome depending on the Schistosoma species involved, the duration and intensity of infection and several host-related factors. A range of diagnostic tests is available to determine Schistosoma infection, including microscopy, antibody detection, antigen detection using the Point-Of-Care Circulating Cathodic Antigen (POC-CCA) test and the Up-Converting Particle Lateral Flow Circulating Anodic Antigen (UCP-LF CAA) test, as well as Nucleic Acid Amplification Tests (NAATs) such as real-time PCR. In this mini review, we discuss these different diagnostic procedures and explore their most appropriate use in context-specific settings. With regard to endemic settings, diagnostic approaches are described based on their suitability for individual diagnosis, monitoring control programs, determining elimination as a public health problem and eventual interruption of transmission. For non-endemic settings, we summarize the most suitable diagnostic approaches for imported cases, either acute or chronic. Additionally, diagnostic options for disease-specific clinical presentations such as genital schistosomiasis and neuro-schistosomiasis are included. Finally, the specific role of diagnostic tests within research settings is described, including a controlled human schistosomiasis infection model and several clinical studies. In conclusion, context-specific settings have different requirements for a diagnostic test, stressing the importance of a well-considered decision of the most suitable diagnostic procedure.

scholarly journals Point-of-Care Diagnostic Tools for Surveillance of SARS-CoV-2 Infections

2021 ◽  
Vol 9 ◽  
Author(s):  
Dhanasekaran Sakthivel ◽  
David Delgado-Diaz ◽  
Laura McArthur ◽  
William Hopper ◽  
Jack S. Richards ◽  
...  
Keyword(s):  
Large Scale ◽  
Clinical Symptoms ◽  
Point Of Care ◽  
Cost Effective ◽  
Nucleic Acid Amplification ◽  
Diagnostic Tools ◽  
Rt Pcr ◽  
Serological Tests ◽  
Polymerase Chain ◽  
Effective Public Health

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a recently emerged and highly contagious virus that causes coronavirus disease 2019 (COVID-19). As of August 24, 2021, there were more than 212 million confirmed COVID-19 cases and nearly 4.4 million deaths reported globally. Early diagnosis and isolation of infected individuals remains one of the most effective public health interventions to control SARS-CoV-2 spread and for effective clinical management of COVID-19 cases. Currently, SARS-CoV-2 infection is diagnosed presumptively based on clinical symptoms and confirmed by detecting the viral RNA in respiratory samples using reverse transcription polymerase chain reaction (RT-PCR). Standard RT-PCR protocols are time consuming, expensive, and technically demanding, which makes them a poor choice for large scale and point-of-care screening in resource-poor settings. Recently developed isothermal nucleic acid amplification tests (iNAAT), antigen and/or serological tests are cost-effective to scale COVID-19 testing at the point-of-care (PoC) and for surveillance activities. This review discusses the development of rapid PoC molecular tools for the detection and surveillance of SARS-CoV-2 infections.

scholarly journals A newly developed paper embedded microchip based on LAMP for rapid multiple detections of foodborne pathogens

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mimi Zhang ◽  
Jinfeng Liu ◽  
Zhiqiang Shen ◽  
Yongxin Liu ◽  
Yang Song ◽  
...  
Keyword(s):  
Centrifugal Force ◽  
Foodborne Pathogens ◽  
Pathogen Detection ◽  
Point Of Care ◽  
Foodborne Pathogen ◽  
Cost Effective ◽  
Reaction Chamber ◽  
Salmonella Spp ◽  
Culture Methods ◽  
Detection Technology

Abstract Background Microfluidic chip detection technology is considered a potent tool for many bioanalytic applications. Rapid detection of foodborne pathogens in the early stages is imperative to prevent the outbreak of foodborne diseases, known as a severe threat to human health. Conventional bacterial culture methods for detecting foodborne pathogens are time-consuming, laborious, and lacking in pathogen diagnosis. To overcome this problem, we have created an embedded paper-based microchip based on isothermal loop amplification (LAMP), which can rapidly and sensitively detect foodborne pathogens. Results We embed paper impregnated with LAMP reagent and specific primers in multiple reaction chambers of the microchip. The solution containing the target pathogen was injected into the center chamber and uniformly distributed into the reaction chamber by centrifugal force. The purified DNA of Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus, and Vibrio parahaemolyticus has been successfully amplified and directly detected on the microchip. The E. coli O157:H7 DNA was identified as low as 0.0134 ng μL− 1. Besides, the potential of this microchip in point-of-care testing was further tested by combining the on-chip sample purification module and using milk spiked with Salmonella spp.. The pyrolyzed milk sample was filtered through a polydopamine-coated paper embedded in the inside of the sample chamber. It was transported to the reaction chamber by centrifugal force for LAMP amplification. Then direct chip detection was performed in the reaction chamber embedded with calcein-soaked paper. The detection limit of Salmonella spp. in the sample measured by the microchip was approximately 12 CFU mL− 1. Conclusion The paper embedded LAMP microchip offers inexpensive, user-friendly, and highly selective pathogen detection capabilities. It is expected to have great potential as a quick, efficient, and cost-effective solution for future foodborne pathogen detection.

scholarly journals Transportation protocols for accurate assessment of microbial burden classification using molecular methods

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amelia Kung ◽  
Jade Chen ◽  
Michael Tomasek ◽  
Dakai Liu ◽  
William Rodgers ◽  
...  
Keyword(s):  
Pathogen Detection ◽  
Point Of Care ◽  
Cost Effective ◽  
Optimal Growth ◽  
Testing Procedure ◽  
Initial Development ◽  
Specimen Collection ◽  
Skin Flora ◽  
Patient Side ◽  
Urine Specimens

AbstractPoint-of-care testing is cost-effective, rapid, and could assist in avoiding hospital visits during a pandemic. However, they present some significant risks that current technologies cannot fully address. Skin flora contamination and insufficient specimen volume are two major limitations preventing self-collection microbiological testing outside of hospital settings. We are developing a hybrid testing procedure to bridge the laboratory test with patient-side specimen collection and transportation for molecular microbial classification of causative bacterial infection and early identification of microbial susceptibility profiles directly from whole blood or urine specimens collected patient-side by health care workers such as phlebotomists in nursing homes or family clinics. This feasibility study presents our initial development efforts, in which we tested various transportation conditions (tubes, temperature, duration) for direct-from-specimen viable pathogen detection to determine the ideal conditions that allowed for differentiation between contaminant and causative bacteria in urine specimens and optimal growth for low-concentration blood specimens after transportation. For direct-from-urine assays, the viable pathogen at the clinical cutoff of 105 CFU/mL was detected after transportation with molecular assays while contaminants (≤ 104 CFU/mL) were not. For direct-from-blood assays, contrived blood samples as low as 0.8 CFU/mL were reported positive after transportation without the need for blood culture.

scholarly journals Eco-Friendly Synthesis of SnO2-Cu Nanocomposites and Evaluation of Their Peroxidase Mimetic Activity

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1798
Author(s):  
Ravi Mani Tripathi ◽  
Sang J. Chung
Keyword(s):  
Ph Value ◽  
Point Of Care ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Cost Effective ◽  
Promising Alternative ◽  
Enzyme Mimetic ◽  
Peroxidase Mimetic ◽  
Point Of Care Diagnostics ◽  
Cost Effective Method

The enzyme mimetic activity of nanomaterials has been applied in colorimetric assays and point-of-care diagnostics. Several nanomaterials have been exploited for their peroxidase mimetic activity toward 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide. However, an efficient nanomaterial for the rapid and strong oxidation of TMB remains a strategic challenge. Therefore, in this study, we developed copper-loaded tin oxide (SnO2-Cu) nanocomposites that rapidly oxidize TMB. These nanocomposites have strong absorption at 650 nm and can be used for highly sensitive colorimetric detection. An environmentally friendly (green), rapid, easy, and cost-effective method was developed for the synthesis of these nanocomposites, which were characterized using ultraviolet-visible, energy-dispersive X-ray, and Fourier-transform infrared spectroscopy, as well as scanning electron microscopy. This is the first green synthesis of SnO2-Cu nanocomposites. Their enzyme mimetic activity, which was first studied here, was found to be strongly dependent on the temperature and pH value of the solution. The synthesized nanocomposites have the advantages of low cost, high stability, and ease of preparation for enzyme mimetic applications. Hence, SnO2-Cu nanocomposites are a promising alternative to peroxidase enzymes in colorimetric point-of-care diagnostics.

scholarly journals Development of a Flow-Free Automated Colorimetric Detection Assay Integrated with Smartphone for Zika NS1

Diagnostics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 42 ◽  
Author(s):  
Md Alamgir Kabir ◽  
Hussein Zilouchian ◽  
Mazhar Sher ◽  
Waseem Asghar
Keyword(s):  
Zika Virus ◽  
Magnetic Beads ◽  
Nonstructural Protein ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Great Promise ◽  
Enzyme Linked Immunosorbent Assay ◽  
Magnetic Actuation ◽  
Superparamagnetic Beads ◽  
Nonstructural Protein 1

The Zika virus (ZIKV) is an emerging flavivirus transmitted to humans by Aedes mosquitoes that can potentially cause microcephaly, Guillain–Barré Syndrome, and other birth defects. Effective vaccines for Zika have not yet been developed. There is a necessity to establish an easily deployable, high-throughput, low-cost, and disposable point-of-care (POC) diagnostic platform for ZIKV infections. We report here an automated magnetic actuation platform suitable for a POC microfluidic sandwich enzyme-linked immunosorbent assay (ELISA) using antibody-coated superparamagnetic beads. The smartphone integrated immunoassay is developed for colorimetric detection of ZIKV nonstructural protein 1 (NS1) antigen using disposable chips to accommodate the reactions inside the chip in microliter volumes. An in-house-built magnetic actuator platform automatically moves the magnetic beads through different aqueous phases. The assay requires a total of 9 min to automatically control the post-capture washing, horseradish peroxidase (HRP) conjugated secondary antibody probing, washing again, and, finally, color development. By measuring the saturation intensity of the developed color from the smartphone captured video, the presented assay provides high sensitivity with a detection limit of 62.5 ng/mL in whole plasma. These results advocate a great promise that the platform would be useful for the POC diagnosis of Zika virus infection in patients and can be used in resource-limited settings.

scholarly journals Detection of Coronaviruses Using RNA Toehold Switch Sensors

2021 ◽  
Vol 22 (4) ◽  
pp. 1772
Author(s):  
Soan Park ◽  
Jeong Wook Lee
Keyword(s):  
Nucleic Acid ◽  
Diagnostic Test ◽  
Pathogen Detection ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Cross Reactivity ◽  
Amplification Method ◽  
Reactivity Test ◽  
Target Rna ◽  
Microbiome Profiling

A rapid, sensitive and simple point-of-care (POC) nucleic acid diagnostic test is needed to prevent spread of infectious diseases. Paper-based toehold reaction, a recently emerged colorimetric POC nucleic acid diagnostic test, has been widely used for pathogen detection and microbiome profiling. Here, we introduce an amplification method called reverse transcription loop-mediated amplification (RT-LAMP) prior to the toehold reaction and modify it to enable more sensitive and faster colorimetric detection of RNA viruses. We show that incorporating the modified RT-LAMP to the toehold reaction detects as few as 120 copies of coronavirus RNA in 70 min. Cross-reactivity test against other coronaviruses indicates this toehold reaction with the modified RT-LAMP is highly specific to the target RNA. Overall, the paper-based toehold switch sensors with the modified RT-LAMP allow fast, sensitive, specific and colorimetric coronavirus detection.

scholarly journals Electrochemical Characterization of Nitrocellulose Membranes towards Bacterial Detection in Water

Proceedings ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 61
Author(s):  
Grégoire Le Brun ◽  
Margo Hauwaert ◽  
Audrey Leprince ◽  
Karine Glinel ◽  
Jacques Mahillon ◽  
...  
Keyword(s):  
Point Of Care ◽  
Colorimetric Detection ◽  
Cost Effective ◽  
Public Healthcare ◽  
Electrical Detection ◽  
Detection Mechanism ◽  
Experimental Proof ◽  
Bacterial Detection ◽  
Cell Wall Binding ◽  
Test Zone

Paper substrates have shown a high potential for development of cost-effective and efficient point-of-care biosensors, essential for public healthcare and environmental diagnostics. Most paper-based biosensors rely on qualitative colorimetric detection schemes with high limits of detection. To overcome this limitation, technologies that combine paper-based substrates and electrochemical detection are being developed to allow for quantification and achieve better performances. In this work, we explore the potential of dielectric measurements towards electrical detection of whole-cell bacteria in nitrocellulose membranes, a paper-derivative. Impedance spectroscopy was considered to characterize the membranes with and without Bacillus thuringiensis cells, used as model microorganism. To specifically target this bacterial strain, phage endolysin cell-wall binding domain (CBD) encoded by a bacteriophage targeting B. thuringiensis were prepared and integrated into the membranes as recognition biointerface. The fluid sample containing the bacteria is conducted in the membrane through passive capillarity, and the bacteria are specifically immobilized in the test zone. Resulting changes of the dielectric properties of the membrane are sensed through impedance changes, highlighting the contribution of ions in the bacterial detection mechanism. This experimental proof-of-concept illustrates the electrical detection of 108 CFU/mL bacteria in low-salinity buffers within 5 min.

scholarly journals On-Chip Detection of the Biomarkers for Neurodegenerative Diseases: Technologies and Prospects

Micromachines ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 629 ◽  
Author(s):  
Chao Song ◽  
Suya Que ◽  
Lucas Heimer ◽  
Long Que
Keyword(s):  
Neurodegenerative Diseases ◽  
Point Of Care ◽  
Cost Effective ◽  
Diagnostic Methods ◽  
The Past ◽  
The World ◽  
Public Health Challenge ◽  
On Chip ◽  
Financial Burdens ◽  
Detection Technologies

Alzheimer’s disease (AD), Parkinson’s disease (PD) and glaucoma are all regarded as neurodegenerative diseases (neuro-DDs) because these diseases are highly related to the degeneration loss of functions and death of neurons with aging. The conventional diagnostic methods such as neuroimaging for these diseases are not only expensive but also time-consuming, resulting in significant financial burdens for patients and public health challenge for nations around the world. Hence early detection of neuro-DDs in a cost-effective and rapid manner is critically needed. For the past decades, some chip-based detection technologies have been developed to address this challenge, showing great potential in achieving point-of-care (POC) diagnostics of neuro-DDs. In this review, chip-based detection of neuro-DDs’ biomarkers enabled by different transducing mechanisms is evaluated.

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