scholarly journals Multiplex Solid-Phase RPA Coupled CRISPR-Based Visual Detection of SARS-CoV-2

2021 ◽  
Author(s):  
Xiaochen Qin ◽  
Yuyuan Zhou ◽  
Ratul Paul ◽  
Yue Wu ◽  
Yaling Liu
Keyword(s):  
Solid Phase ◽  
Dna Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Control Sample ◽  
Virus Detection ◽  
Cost Effective ◽  
Analytical Sensitivity ◽  
One Pot ◽  
Hpv Dna

COVID-19 has challenged the world's public health and led to over 4.5 million deaths. A rapid, sensitive, and cost-effective point-of-care virus detection device is crucial to the control and surveillance of the contagious severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic. Here we demonstrate a solid phase isothermal recombinase polymerase amplification coupled CRISPR-based (spRPA-CRISPR) assay for on-chip multiplexed, sensitive, and visual COVID-19 DNA detection. By targeting the SARS-CoV-2 structure protein encoded genomes, two specific genes were simultaneously detected with the control sample without cross-interaction with other sequences. The endpoint signal can be directly visualized for rapid detection of COVID-19. The amplified target sequences were immobilized on the one-pot device surface and detected using the mixed Cas12a-crRNA collateral cleavage of reporter released fluorescent signal when specific genes were recognized. The system was tested with samples of a broad range of concentrations (20 to 2x105 copies) and showed analytical sensitivity down to 20 copies per reaction. Furthermore, a low-cost LED UV flashlight (~$12) was used to provide a visible SARS-CoV-2 detection signal of the spRPA-CRISPR assay which could be purchased online easily. Thus, our platform provides a sensitive and easy-to-read multiplexed gene detection method with the capacity to specifically identify low concentration genes. Similar CRISPR biosensor chips can support a broad range of applications such as HPV DNA detection, influenza SARS-CoV-2 multiplex detection, and other infectious disease testing assays.

scholarly journals Methods of Respiratory Virus Detection: Advances towards Point-of-Care for Early Intervention

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 697
Author(s):  
Siming Lu ◽  
Sha Lin ◽  
Hongrui Zhang ◽  
Liguo Liang ◽  
Shien Shen
Keyword(s):  
Viral Load ◽  
Respiratory Virus ◽  
Viral Infections ◽  
Point Of Care ◽  
Human Life ◽  
Low Cost ◽  
Virus Detection ◽  
Frequent Monitoring ◽  
User Friendly ◽  
New Strategies

Respiratory viral infections threaten human life and inflict an enormous healthcare burden worldwide. Frequent monitoring of viral antibodies and viral load can effectively help to control the spread of the virus and make timely interventions. However, current methods for detecting viral load require dedicated personnel and are time-consuming. Additionally, COVID-19 detection is generally relied on an automated PCR analyzer, which is highly instrument-dependent and expensive. As such, emerging technologies in the development of respiratory viral load assays for point-of-care (POC) testing are urgently needed for viral screening. Recent advances in loop-mediated isothermal amplification (LAMP), biosensors, nanotechnology-based paper strips and microfluidics offer new strategies to develop a rapid, low-cost, and user-friendly respiratory viral monitoring platform. In this review, we summarized the traditional methods in respiratory virus detection and present the state-of-art technologies in the monitoring of respiratory virus at POC.

scholarly journals One-pot synthesis of a stable and cost-effective silver particle-free ink for inkjet-printed flexible electronics

2020 ◽  
Vol 8 (46) ◽  
pp. 16443-16451
Author(s):  
Wendong Yang ◽  
Florian Mathies ◽  
Eva L. Unger ◽  
Felix Hermerschmidt ◽  
Emil J. W. List-Kratochvil
Keyword(s):  
Flexible Electronics ◽  
Silver Particle ◽  
Low Cost ◽  
Cost Effective ◽  
Good Stability ◽  
Flexible Substrates ◽  
One Pot ◽  
One Pot Synthesis ◽  
Do It Yourself

A do-it-yourself silver particle-free ink is presented, which shows good stability, low cost and excellent printability. The ink is formulated in selected alcohols. Highly conductive silver patterns were printed on both glass and flexible substrates.

scholarly journals Application of Flexible Display Technology to Low Cost Multiplexed Point-of-Care Medical Diagnostic Testing

2016 ◽  
Vol 2 (3_suppl) ◽  
pp. 14s-14s
Author(s):  
Benjamin A. Katchman ◽  
Joseph T. Smith ◽  
Jennifer Blain Christen ◽  
Karen S. Anderson
Keyword(s):  
Intellectual Property ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Manufacturing Technology ◽  
Analytical Sensitivity ◽  
State University ◽  
Arizona State University ◽  
New Approach ◽  
Display Technology

Abstract 62 One of the key roadblocks limiting the transition of high-sensitivity and high-specificity point-of-care technologies from the research laboratory to wide spread use is the availability of a low-cost-high-volume manufacturing technology. This work presents a new interdisciplinary approach combining low cost commercial display manufacturing technology with programmable high density protein microarray printing technology to fabricate disposable point-of-care immunosensors with clinical level sensitivity. Our approach is designed to leverage advances in commercial display technology to reduce pre-functionalized biosensor substrate costs to pennies per cm2, as well as to leverage the display industry’s ability to manufacture an immense number of low cost consumer electronic products annually. For this work, we demonstrate that our new approach can offer diagnostic sensitivity at or below 10 pg/mL, which approaches the lower limit of detection of typical clinical laboratory instrumentation. Our new approach is also designed to overcome the limited analytical sensitivity of existing POC devices (>100x improved sensitivity). It also contains new capability for multiplexed biomarker detection (>10 antigens) in a single low cost POC device through an innovative disposable and scalable architecture, based on flat panel display technology. Here, we demonstrate multiplexed detection of antibodies to the HPV16 proteins E2, E6, and E7, which are circulating biomarkers for cervical as well as head and neck cancers. This detection technology has 100 percent correlation to our current laboratory-based measurement instrumentation. AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST: Benjamin A. Katchman Patents, Royalties, Other Intellectual Property: Arizona State University Joseph T. Smith Patents, Royalties, Other Intellectual Property: Arizona State University Jennifer Blain Christen Patents, Royalties, Other Intellectual Property: Arizona State University Karen S. Anderson Stock or Other Ownership: Provista Diagnostics Consulting or Advisory Role: Provista Diagnostics Patents, Royalties, Other Intellectual Property: Arizona State University

A Green Alternative for Aryl Iodide Preparation from Aromatic Amines

2020 ◽  
Vol 17 (2) ◽  
pp. 131-135
Author(s):  
Zohreh Shahnavaz ◽  
Lia Zaharani ◽  
Mohd Rafie Johan ◽  
Nader Ghaffari Khaligh
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
Raw Material ◽  
Diazonium Salts ◽  
Separation And Purification ◽  
One Pot ◽  
Aryl Iodide ◽  
Aryl Iodides ◽  
The One

Background: In continuation of our previous work and the applications of saccharin, we encouraged to investigate the one-pot synthesis of the aryl iodides by the diazotization of the arene diazonium saccharin salts. Objective: Arene diazonium salts play an important role in organic synthesis as intermediate and a wide variety of aromatic compounds have been prepared using them. A serious drawback of arene diazonium salts is their instability in a dry state; therefore, they must be stored and handled carefully to avoid spontaneous explosion and other hazard events. Methods: The arene diazonium saccharin salts were prepared as active intermediates in situ through the reaction of various aryl amines with tert-butyl nitrite (TBN) in the presence of saccharin (Sac–H). Then, in situ obtained intermediates were used into the diazotization step without separation and purification in the current protocol. Results: A variety of aryl iodides were synthesized at a greener and low-cost method in the presence of TBN, Sac–H, glacial acetic acid, and TEAI. Conclusion: In summary, a telescopic reaction is developed for the synthesis of aryl iodides. The current methodology is safe, cost-effective, broad substrate scope, and metal-free. All used reagents are commercially available and inert to moisture and air. Also, the saccharine and tetraethylammonium cation could be partially recovered from the reaction residue, which reduces waste generation, energy consumption, raw material, and waste disposal costs.

scholarly journals All-in-One Dual CRISPR-Cas12a (AIOD-CRISPR) Assay: A Case for Rapid, Ultrasensitive and Visual Detection of Novel Coronavirus SARS-CoV-2 and HIV virus at the Point of Care

2020 ◽  
Author(s):  
Xiong Ding ◽  
Kun Yin ◽  
Ziyue Li ◽  
Rajesh V. Lalla ◽  
Enrique Ballesteros ◽  
...  
Keyword(s):  
Visual Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Detection Sensitivity ◽  
Disease Spread ◽  
Assay Method ◽  
One Pot ◽  
Dna And Rna ◽  
Novel Coronavirus ◽  
Hiv 1

Abstract The recent outbreak of novel Coronavirus (SARS-CoV-2), the causative agent of COVID-19 disease, has spread rapidly all over the world. Human immunodeficiency virus (HIV) is another deadly virus and causes acquired immunodeficiency syndrome (AIDS). Rapid and early detection of these viruses will facilitate early intervention and prevent disease spread. Here, we present an All-In-One Dual CRISPR-Cas12a (termed "AIOD-CRISPR") assay method for simple, rapid, ultrasensitive, specific, one-pot, and visual detection of coronavirus SARS-CoV- 2 and HIV-1 virus. In our AIOD-CRISPR assay, a pair of crRNAs was introduced to initiate dual CRISPR-Cas12a-based detection and improve both detection sensitivity and fluorescence signals. The AIOD-CRISPR assay method was utilized to detect nucleic acids (DNA and RNA) of the SARS-CoV-2 and HIV-1 with a sensitivity of few copies. We validated our AIOD-CRISPR method by using COVID-19 swab samples and obtained consistent results with that of RT-PCR method. More importantly, we successfully demonstrated to use a low- cost hand warmer (~$ 0.3) as an incubator of our AIOD-CRISPR assay and detect COVID-19 patient samples within 20 minutes, enabling an instrument-free, visual detection of COVID-19 at the point of care. Thus, our method has significant potential for developing next-generation point-of-care molecular diagnostics.

scholarly journals A Disposable Paper-Based Electrochemical Sensor Made of Pencil Graphite and Its Modification with Au for Detection of Glucose in Alkaline Solutions

2020 ◽  
Author(s):  
Mustafa Sen
Keyword(s):  
Environmental Monitoring ◽  
Electrochemical Sensor ◽  
Point Of Care ◽  
Low Cost ◽  
Cost Effective ◽  
Alkaline Solutions ◽  
Glucose Detection ◽  
Electrochemical Modification ◽  
Point Of Care Diagnostics

Paper-based sensors have great potential to be used in a variety of fields ranging from environmental monitoring to clinical and point-of-care diagnostics. These sensors are disposable, cost effective, flexible and easy to use. The aim of this study was to fabricate a low cost, disposable, reliable and easy to use paper-based electrochemical sensor and its electrochemical modification with nanostructured Au for glucose detection in alkaline solutions.

scholarly journals Rapid comparative evaluation of SARS-CoV-2 rapid point-of-care antigen tests

2021 ◽  
Author(s):  
Anna Denzler ◽  
Max L. Jacobs ◽  
Viktoria Witte ◽  
Paul Schnitzler ◽  
Claudia M. Denkinger ◽  
...  
Keyword(s):  
Point Of Care ◽  
False Negative ◽  
Control Sample ◽  
Test Sample ◽  
Published Data ◽  
Assessment Procedure ◽  
Analytical Sensitivity ◽  
Viral Loads ◽  
Comparison Results ◽  
Analytical Sensitivities

Background: Currently, more than 500 different AgPOCTs for SARS-CoV-2 diagnostics are on sale, for many of which no data about sensitivity other than self-acclaimed values by the manufacturers are available. In many cases these do not reflect real-life diagnostic sensitivities. Therefore, manufacturer-independent quality checks of available AgPOCTs are needed, given the potential implications of false-negative results. Objective: The objective of this study was to develop a scalable approach for direct comparison of the analytical sensitivities of commercially available SARS-CoV-2 antigen point-of-care tests (AgPOCTs) in order to rapidly identify poor performing products. Methods: We present a methodology for quick assessment of the sensitivity of SARS-CoV-2 lateral flow test stripes suitable for quality evaluation of many different products. We established reference samples with high, medium and low SARS-CoV-2 viral loads along with a SARS-CoV-2 negative control sample. Test samples were used to semi-quantitatively assess the analytical sensitivities of 32 different commercial AgPOCTs in a head-to-head comparison. Results: Among 32 SARS-CoV-2 AgPOCTs tested, we observe sensitivity differences across a broad range of viral loads (~7.0*10⁸ to ~1.7*10⁵ SARS-CoV-2 genome copies per ml). 23 AgPOCTs detected the Ct25 test sample (~1.4*10⁶ copies/ ml), while only five tests detected the Ct28 test sample (~1.7*10⁵ copies/ ml). In the low range of analytical sensitivity we found three saliva spit tests only delivering positive results for the Ct21 sample (~2.2*10⁷ copies/ ml). Comparison with published data support our AgPOCT ranking. Importantly, we identified an AgPOCT offered in many local drugstores and supermarkets, which did not reliably recognize the sample with highest viral load (Ct16 test sample with ~7.0*10⁸ copies/ ml) leading to serious doubts in its usefulness in SARS-CoV-2 diagnostics. Conclusion: The rapid sensitivity assessment procedure presented here provides useful estimations on the analytical sensitivities of 32 AgPOCTs and identified a widely-spread AgPOCT with concerningly low sensitivity.

scholarly journals Amberlite IR-120 Catalyzed Green and Efficient One-Pot Synthesis of Benzylpyrazolyl Coumarin in Aqueous Medium

2021 ◽  
Vol 10 (3) ◽  
pp. 2525-2534
Keyword(s):  
Reaction Time ◽  
Aqueous Medium ◽  
Ethyl Acetoacetate ◽  
Low Cost ◽  
Cost Effective ◽  
High Yield ◽  
Phenyl Hydrazine ◽  
One Pot ◽  
Time Operation ◽  
Effective Synthesis

An efficient, green, and cost-effective synthesis of benzylpyrazolyl coumarin by one-pot four-component condensation of hydrazine hydrate or phenyl hydrazine, ethyl acetoacetate, aromatic aldehyde, and 4-hydroxycoumarin in the presence of Amberlite IR-120 as a catalyst in an aqueous medium has been reported. Shorter reaction time, operation simplicity, low cost of catalyst, and aqueous medium are key advantages of this method for synthesizing benzylpyrazolyl coumarin in moderate to high yield.

scholarly journals Deep Learning-Enabled Point-of-Care Sensing Using Multiplexed Paper-Based Sensors

2019 ◽  
Author(s):  
Zachary Ballard ◽  
Hyou-Arm Joung ◽  
Artem Goncharov ◽  
Jesse Liang ◽  
Karina Nugroho ◽  
...  
Keyword(s):  
Machine Learning ◽  
Deep Learning ◽  
Point Of Care ◽  
Low Cost ◽  
High Sensitivity ◽  
Cost Effective ◽  
Serum Samples ◽  
Cvd Risk ◽  
Medical Test ◽  
Sensing Membrane

ABSTRACTWe present a deep learning-based framework to design and quantify point-of-care sensors. As its proof-of-concept and use-case, we demonstrated a low-cost and rapid paper-based vertical flow assay (VFA) for high sensitivity C-Reactive Protein (hsCRP) testing, a common medical test used for quantifying the degree of inflammation in patients at risk of cardio-vascular disease (CVD). A machine learning-based sensor design framework was developed for two key tasks: (1) to determine an optimal configuration of immunoreaction spots and conditions, spatially-multiplexed on a paper-based sensing membrane, and (2) to accurately infer the target analyte concentration based on the signals of the optimal VFA configuration. Using a custom-designed mobile-phone based VFA reader, a clinical study was performed with 85 human serum samples to characterize the quantification accuracy around the clinically defined cutoffs for CVD risk stratification. Results from blindly-tested VFAs indicate a competitive coefficient of variation of 11.2% with a linearity of R2 = 0.95; in addition to the success in the high-sensitivity CRP range (i.e., 0-10 mg/L), our results further demonstrate a mitigation of the hook-effect at higher CRP concentrations due to the incorporation of antigen capture spots within the multiplexed sensing membrane of the VFA. This paper-based computational VFA that is powered by deep learning could expand access to CVD health screening, and the presented machine learning-enabled sensing framework can be broadly used to design cost-effective and mobile sensors for various point-of-care diagnostics applications.

scholarly journals Suppressing Non-Specific Binding of Proteins onto Electrode Surfaces in the Development of Electrochemical Immunosensors

Biosensors ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 15 ◽  
Author(s):  
Jesús Contreras-Naranjo ◽  
Oscar Aguilar
Keyword(s):  
Solid Phase ◽  
Specific Binding ◽  
Point Of Care ◽  
Low Cost ◽  
Electrochemical Techniques ◽  
High Specificity ◽  
Electrode Surfaces ◽  
Solid Phase Immunoassay ◽  
Electrochemical Immunosensors ◽  
Complex Phenomena

Electrochemical immunosensors, EIs, are systems that combine the analytical power of electrochemical techniques and the high selectivity and specificity of antibodies in a solid phase immunoassay for target analyte. In EIs, the most used transducer platforms are screen printed electrodes, SPEs. Some characteristics of EIs are their low cost, portability for point of care testing (POCT) applications, high specificity and selectivity to the target molecule, low sample and reagent consumption and easy to use. Despite all these attractive features, still exist one to cover and it is the enhancement of the sensitivity of the EIs. In this review, an approach to understand how this can be achieved is presented. First, it is necessary to comprise thoroughly all the complex phenomena that happen simultaneously in the protein-surface interface when adsorption of the protein occurs. Physicochemical properties of the protein and the surface as well as the adsorption phenomena influence the sensitivity of the EIs. From this point, some strategies to suppress non-specific binding, NSB, of proteins onto electrode surfaces in order to improve the sensitivity of EIs are mentioned.

Sign in / Sign up

Export Citation Format

Share Document