scholarly journals Minimally instrumented SHERLOCK (miSHERLOCK) for CRISPR-based point-of-care diagnosis of SARS-CoV-2 and emerging variants

2021 ◽  
Vol 7 (32) ◽  
pp. eabh2944
Author(s):  
Helena de Puig ◽  
Rose A. Lee ◽  
Devora Najjar ◽  
Xiao Tan ◽  
Luis R. Soekensen ◽  
...  
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Smartphone Application ◽  
Modular System ◽  
User Needs ◽  
Multiplexed Detection ◽  
Highly Sensitive ◽  
Current Point ◽  
Automated Interpretation ◽  
User Actions

The COVID-19 pandemic highlights the need for diagnostics that can be rapidly adapted and deployed in a variety of settings. Several SARS-CoV-2 variants have shown worrisome effects on vaccine and treatment efficacy, but no current point-of-care (POC) testing modality allows their specific identification. We have developed miSHERLOCK, a low-cost, CRISPR-based POC diagnostic platform that takes unprocessed patient saliva; extracts, purifies, and concentrates viral RNA; performs amplification and detection reactions; and provides fluorescent visual output with only three user actions and 1 hour from sample input to answer out. miSHERLOCK achieves highly sensitive multiplexed detection of SARS-CoV-2 and mutations associated with variants B.1.1.7, B.1.351, and P.1. Our modular system enables easy exchange of assays to address diverse user needs and can be rapidly reconfigured to detect different viruses and variants of concern. An adjunctive smartphone application enables output quantification, automated interpretation, and the possibility of remote, distributed result reporting.

scholarly journals Trimodal Waveguide Demonstration and Its Implementation as a High Order Mode Interferometer for Sensing Application

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2821 ◽  
Author(s):  
Jhonattan C. Ramirez ◽  
Lucas H. Gabrielli ◽  
Laura M. Lechuga ◽  
Hugo E. Hernandez-Figueroa
Keyword(s):  
Free Spectral Range ◽  
Point Of Care ◽  
Low Cost ◽  
High Order Mode ◽  
Sio2 Substrate ◽  
Polymer Waveguide ◽  
Sensing Applications ◽  
Highly Sensitive ◽  
Different Types ◽  
Mode Order

This work implements and demonstrates an interferometric transducer based on a trimodal optical waveguide concept. The readout signal is generated from the interference between the fundamental and second-order modes propagating on a straight polymer waveguide. Intuitively, the higher the mode order, the larger the fraction of power (evanescent field) propagating outside the waveguide core, hence the higher the sensitivity that can be achieved when interfering against the strongly confined fundamental mode. The device is fabricated using the polymer SU-8 over a SiO2 substrate and shows a free spectral range of 20.2 nm and signal visibility of 5.7 dB, reaching a sensitivity to temperature variations of 0.0586 dB/ ∘ C. The results indicate that the proposed interferometer is a promising candidate for highly sensitive, compact and low-cost photonic transducer for implementation in different types of sensing applications, among these, point-of-care.

scholarly journals A low-cost smartphone-based platform for highly sensitive point-of-care testing with persistent luminescent phosphors

Lab on a Chip ◽  
2017 ◽  
Vol 17 (6) ◽  
pp. 1051-1059 ◽  
Author(s):  
Andrew S. Paterson ◽  
Balakrishnan Raja ◽  
Vinay Mandadi ◽  
Blane Townsend ◽  
Miles Lee ◽  
...  
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Test Strip ◽  
Lateral Flow ◽  
Point Of Care Testing ◽  
Flow Test ◽  
Highly Sensitive ◽  
Lateral Flow Test ◽  
Gated Imaging

Time-gated imaging on a smartphone of a lateral flow test strip run with persistent luminescent nanophosphors.

scholarly journals Detection and quantification of Mycobacterium tuberculosis antigen CFP10 in serum and urine for the rapid diagnosis of active tuberculosis disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marva Seifert ◽  
Eva Vargas ◽  
Victor Ruiz-Valdepeñas Montiel ◽  
Joseph Wang ◽  
Timothy C. Rodwell ◽  
...  
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Specific Antigen ◽  
Active Tuberculosis ◽  
Serum Samples ◽  
Tuberculosis Patients ◽  
Tuberculosis Antigen ◽  
Highly Sensitive ◽  
Tuberculosis Disease ◽  
Serum And Urine

AbstractOutside of the ongoing COVID-19 pandemic, tuberculosis is the leading cause of infectious disease mortality globally. Currently, there is no commercially available point-of-care diagnostic that is rapid, inexpensive, and highly sensitive for the diagnosis of active tuberculosis disease. Here we describe the development and optimization of a novel, highly sensitive prototype bioelectronic tuberculosis antigen (BETA) assay to detect tuberculosis-specific antigen, CFP10, in small-volume serum and urine samples. In this proof-of-concept study we evaluated the performance of the BETA assay using clinical specimens collected from presumptive tuberculosis patients from three independent cohorts. Circulating CFP10 antigen was detected in ALL serum (n = 19) and urine (n = 3) samples from bacteriologically confirmed tuberculosis patients who were untreated or had less than one week of treatment at time of serum collection, successfully identifying all culture positive tuberculosis patients. No CFP10 antigen was detected in serum (n = 7) or urine (n = 6) samples from individuals who were determined to be negative for tuberculosis disease. Additionally, antigen quantification using the BETA assay of paired serum samples collected from tuberculosis patients (n = 8) both before and after treatment initiation, indicate consistently declining within-person levels of CFP10 antigen during treatment. This novel, low-cost assay demonstrates potential as a rapid, non-sputum-based, point-of-care tool for the diagnosis of tuberculosis disease.

scholarly journals Direct diagnostic testing of SARS-CoV-2 without the need for prior RNA extraction

2020 ◽  
Author(s):  
Shan Wei ◽  
Esther Kohl ◽  
Alexandre Djandji ◽  
Stephanie Morgan ◽  
Susan Whittier ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Diagnostic Testing ◽  
Rna Extraction ◽  
Nucleic Acid Amplification ◽  
Nasopharyngeal Swab ◽  
Viral Transport ◽  
Extraction Step ◽  
Highly Sensitive

AbstractThe COVID-19 pandemic has resulted in an urgent global need for rapid, point-of-care diagnostic testing. Existing methods for nucleic acid amplification testing (NAAT) require an RNA extraction step prior to amplification of the viral RNA. This step necessitates the use of a centralized laboratory or complex and costly proprietary cartridges and equipment, and thereby prevents low-cost, scalable, point-of-care testing. We report the development of a highly sensitive and robust, easy-to-implement, SARS-CoV-2 test that utilizes isothermal amplification and can be run directly on viral transport media following a nasopharyngeal swab without the need for prior RNA extraction. Our assay provides visual results in 30 min with 85% sensitivity, 100% specificity, and a limit of detection (LoD) of 2.5 copies/μl, and can be run using a simple heat block.

A portable point-of-care testing system to diagnose lung cancer through the detection of exosomal miRNA in urine and saliva

2020 ◽  
Vol 56 (63) ◽  
pp. 8968-8971 ◽  
Author(s):  
Ping Zhou ◽  
Fei Lu ◽  
Jianbo Wang ◽  
Kaiye Wang ◽  
Bo Liu ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Point Of Care ◽  
Low Cost ◽  
Testing System ◽  
Point Of Care Testing ◽  
Lung Cancers ◽  
Non Invasive ◽  
Diagnose Lung Cancer ◽  
Highly Sensitive ◽  
Exosomal Mirna

A low-cost, easy-to-operate, highly sensitive and effective lung cancer diagnostic kit (LCDK) was developed, and can realize non-invasive detection of early-, middle- and late-stage lung cancers using clinical salivary and urine samples.

An enhanced fluorescent probe through the strategy of MgWO4 nanosheets to enhance terbium ion luminescence for highly sensitive and point-of-care visual quantitative testing of ciprofloxacin integrated with a low-cost smartphone-based platform

The Analyst ◽  
2021 ◽  
Author(s):  
Jingfei Zhang ◽  
Guoyue Shi ◽  
Yu Zhang
Keyword(s):  
Hydrothermal Method ◽  
Fluorescent Probe ◽  
Point Of Care ◽  
Low Cost ◽  
Simple Hydrothermal Method ◽  
Highly Sensitive ◽  
Terbium Ion

In this work, MgWO4 nanosheets have successfully been synthesized by a simple hydrothermal method, and the morphology and composition of MgWO4 nanosheets are characterized by SEM, TEM, XPS, UV-vis. The...

scholarly journals Highly sensitive interleukin 6 detection by employing commercially ready liposomes in an LFA format

2021 ◽  
Author(s):  
Simone Rink ◽  
Barbara Kaiser ◽  
Mark-Steven Steiner ◽  
Axel Duerkop ◽  
Antje J. Baeumner
Keyword(s):  
Interleukin 6 ◽  
Point Of Care ◽  
Low Cost ◽  
Ease Of Use ◽  
Commercial Application ◽  
Sulforhodamine B ◽  
Highly Sensitive ◽  
Order Of Magnitude ◽  
Lateral Flow Assays ◽  
Commercial Applications

AbstractRecent years have confirmed the ubiquitous applicability of lateral flow assays (LFA) in point-of-care testing (POCT). To make this technology available for low abundance analytes, strategies towards lower limits of detections (LOD), while maintaining the LFA’s ease of use, are still being sought. Here, we demonstrate how liposomes can significantly improve the LOD of traditional gold nanoparticle (AuNP)–based assays while fully supporting a ready-to-use system for commercial application. We fine-tuned liposomes towards photometric and fluorescence performance on the synthesis level and applied them in an established interleukin 6 (IL-6) immunoassay normally using commercial AuNP labels. IL-6’s low abundance (< 10 pg mL−1) and increasing relevance as prognostic marker for infections make it an ideal model analyte. It was found that liposomes with a high encapsulant load (150 mmol L−1 sulforhodamine B (SRB)) easily outperform AuNPs in photometric LFAs. Specifically, liposomes with 350 nm in diameter yield a lower LOD even in complex matrices such as human serum below the clinically relevant range (7 pg mL−1) beating AuNP by over an order of magnitude (81 pg mL−1). When dehydrated on the strip, liposomes maintained their signal performance for over a year even when stored at ambient temperature and indicate extraordinary stability of up to 8 years when stored as liquid. Whereas no LOD improvement was obtained by exploiting the liposomes’ fluorescence, an extraordinary gain in signal intensity was achieved upon lysis which is a promising feature for high-resolution and low-cost detection devices. Minimizing the procedural steps by inherently fluorescent liposomes, however, is not feasible. Finally, liposomes are ready for commercial applications as they are easy to mass-produce and can simply be substituted for the ubiquitously used AuNPs in the POCT market. Graphical abstract

scholarly journals Validation of a point-of-care rapid diagnostic test for hepatitis C for use in resource-limited settings

2019 ◽  
Vol 11 (4) ◽  
pp. 314-315
Author(s):  
James S Leathers ◽  
Maria Belen Pisano ◽  
Viviana Re ◽  
Gertine van Oord ◽  
Amir Sultan ◽  
...  
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Rapid Diagnosis ◽  
Direct Acting Antivirals ◽  
Resource Limited Settings ◽  
Rapid Diagnosis Test ◽  
Resource Limited ◽  
Specificity And Sensitivity ◽  
Hcv Screening ◽  
Direct Acting

Abstract Background Treatment of HCV with direct-acting antivirals has enabled the discussion of HCV eradication worldwide. Envisioning this aim requires implementation of mass screening in resource-limited areas, usually constrained by testing costs. Methods We validated a low-cost, rapid diagnosis test (RDT) for HCV in three different continents in 141 individuals. Results The HCV RDT showed 100% specificity and sensitivity across different samples regardless of genotype or viral load (in samples with such information, 90%). Conclusions The HCV test validated in this study can allow for HCV screening in areas of need when properly used.

scholarly journals A rapid, accurate, scalable, and portable testing system for COVID-19 diagnosis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guanhua Xun ◽  
Stephan Thomas Lane ◽  
Vassily Andrew Petrov ◽  
Brandon Elliott Pepa ◽  
Huimin Zhao
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
High Volume ◽  
N Gene ◽  
Testing System ◽  
Target Sequence ◽  
One Pot ◽  
Sequence Detection ◽  
Highly Sensitive ◽  
Speed Accuracy

AbstractThe need for rapid, accurate, and scalable testing systems for COVID-19 diagnosis is clear and urgent. Here, we report a rapid Scalable and Portable Testing (SPOT) system consisting of a rapid, highly sensitive, and accurate assay and a battery-powered portable device for COVID-19 diagnosis. The SPOT assay comprises a one-pot reverse transcriptase-loop-mediated isothermal amplification (RT-LAMP) followed by PfAgo-based target sequence detection. It is capable of detecting the N gene and E gene in a multiplexed reaction with the limit of detection (LoD) of 0.44 copies/μL and 1.09 copies/μL, respectively, in SARS-CoV-2 virus-spiked saliva samples within 30 min. Moreover, the SPOT system is used to analyze 104 clinical saliva samples and identified 28/30 (93.3% sensitivity) SARS-CoV-2 positive samples (100% sensitivity if LoD is considered) and 73/74 (98.6% specificity) SARS-CoV-2 negative samples. This combination of speed, accuracy, sensitivity, and portability will enable high-volume, low-cost access to areas in need of urgent COVID-19 testing capabilities.

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