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1.
Virus Res ; 305: 198575, 2021 11.
Article in English | MEDLINE | ID: covidwho-1433886

ABSTRACT

Saliva is an appropriate specimen for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) diagnosis. The possibility of pooling samples of saliva, using non-invasive bibula strips for sampling, was explored employing Bovine coronavirus (BCoV) spiked saliva. In laboratory, up to 30 saliva-soaked strips were pooled in a single tube with 2 mL of medium. After quick adsorption with the medium and vortexing, the liquid was collected and tested with a quantitative molecular assay to quantify viral RNA genome copies. On testing of single and pooled strips, the difference between the median threshold cycles (Ct) value of test performed on the single positive saliva sample and the median Ct value obtained on the pool of 30 strips, was 3.21 cycles. Saliva pooling with bibula strips could allow monitoring of COVID-19 on a large scale, reducing costs for the health bodies in terms of medical material and skilled personnel. Finally, saliva sampling is noninvasive and less traumatic than nasopharyngeal swabs and can be self-collected.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Coronavirus, Bovine/genetics , Genome, Viral , RNA, Viral/genetics , Specimen Handling/methods , COVID-19/virology , COVID-19 Nucleic Acid Testing/economics , Humans , Limit of Detection , Reagent Strips/analysis , SARS-CoV-2/genetics , Saliva/virology
2.
Drug Test Anal ; 13(4): 734-746, 2021 Apr.
Article in English | MEDLINE | ID: covidwho-1107629

ABSTRACT

The illicit drug overdose crisis in North America continues to devastate communities with fentanyl detected in the majority of illicit drug overdose deaths. The COVID-19 pandemic has heightened concerns of even greater unpredictability in the drug supplies and unprecedented rates of overdoses. Portable drug-checking technologies are increasingly being integrated within overdose prevention strategies. These emerging responses are raising new questions about which technologies to pursue and what service models can respond to the current risks and contexts. In what has been referred to as the epicenter of the overdose crisis in Canada, a multi-technology platform for drug checking is being piloted in community settings using a suite of chemical analytical methods to provide real-time harm reduction. These include infrared absorption, Raman scattering, gas chromatography with mass spectrometry, and antibody-based test strips. In this Perspective, we illustrate some advantages and challenges of using multiple techniques for the analysis of the same sample, and provide an example of a data analysis and visualization platform that can unify the presentation of the results and enable deeper analysis of the results. We also highlight the implementation of a various service models that co-exist in a research setting, with particular emphasis on the way that drug checking technicians and harm reduction workers interact with service users. Finally, we provide a description of the challenges associated with data interpretation and the communication of results to a diverse audience.


Subject(s)
Drug Overdose/diagnosis , Illicit Drugs/analysis , Substance Abuse Detection/methods , COVID-19/epidemiology , Drug Overdose/epidemiology , Gas Chromatography-Mass Spectrometry/instrumentation , Gas Chromatography-Mass Spectrometry/methods , Humans , Pilot Projects , Point-of-Care Testing , Reagent Strips/analysis , Spectrophotometry, Infrared/instrumentation , Spectrophotometry, Infrared/methods , Spectrum Analysis, Raman/instrumentation , Spectrum Analysis, Raman/methods , Substance Abuse Detection/instrumentation
3.
Biosens Bioelectron ; 171: 112753, 2021 Jan 01.
Article in English | MEDLINE | ID: covidwho-885210

ABSTRACT

A polyethyleneimine (PEI)-assisted copper in-situ growth (CISG) strategy was proposed as a controlled signal amplification strategy to enhance the sensitivity of gold nanoparticle-based lateral flow sensors (AuNP-LFS). The controlled signal amplification is achieved by introducing PEI as a structure-directing agent to regulate the thermodynamics of anisotropic Cu nanoshell growth on the AuNP surface, thus controlling shape and size of the resultant AuNP@Cu core-shell nanostructures and confining free reduction and self-nucleation of Cu2+ for improved reproducibility and decreased false positives. The PEI-CISG-enhanced AuNP-LFS showed ultrahigh sensitivities with the detection limits of 50 fg mL-1 for HIV-1 capsid p24 antigen and 6 CFU mL-1 for Escherichia coli O157:H7. We further demonstrated its clinical diagnostic efficacy by configuring PEI-CISG into a commercial AuNP-LFS detection kit for SARS-CoV-2 antibody detection. Altogether, this work provides a reliable signal amplification platform to dramatically enhance the sensitivity of AuNP-LFS for rapid and accurate diagnostics of various infectious diseases.


Subject(s)
Biosensing Techniques/methods , Copper/chemistry , Coronavirus Infections/diagnosis , Escherichia coli Infections/diagnosis , Gold/chemistry , HIV Infections/diagnosis , Pneumonia, Viral/diagnosis , Betacoronavirus/isolation & purification , Biosensing Techniques/instrumentation , COVID-19 , COVID-19 Testing , Clinical Laboratory Techniques , Equipment Design , Escherichia coli O157/isolation & purification , HIV Core Protein p24/analysis , HIV-1/isolation & purification , Humans , Limit of Detection , Metal Nanoparticles/chemistry , Metal Nanoparticles/ultrastructure , Oxidation-Reduction , Pandemics , Polyethyleneimine/chemistry , Reagent Strips/analysis , SARS-CoV-2
4.
Lab Chip ; 20(22): 4255-4261, 2020 11 10.
Article in English | MEDLINE | ID: covidwho-872742

ABSTRACT

COVID-19 is a widespread and highly contagious disease in the human population. COVID-19 is caused by SARS-CoV-2 infection. There is still a great demand for point-of-care tests for detection, epidemic prevention and epidemiological investigation, both now and after the epidemic. We present a lateral flow immunoassay kit based on a selenium nanoparticle-modified SARS-CoV-2 nucleoprotein, which detects anti-SARS-CoV-2 IgM and anti-SARS-CoV-2 IgG in human serum, and the results can be read by the naked eye in 10 minutes. We expressed and purified the SARS-CoV-2 nucleoprotein in HEK293 cells, with a purity of 98.14% and a concentration of 5 mg mL-1. Selenium nanoparticles were synthesized by l-ascorbic acid reduction of seleninic acid at room temperature. After conjugation with the nucleoprotein, a lateral flow kit was successfully prepared. The IgM and IgG detection limits of the lateral flow kit reached 20 ng mL-1 and 5 ng mL-1, respectively, in human serum. A clinical study sample comprising 90 COVID-19-diagnosed patients and 263 non-infected controls was used to demonstrate a sensitivity and specificity of 93.33% and 97.34%, respectively, based on RT-PCR and clinical results. No cross-reactions with rheumatoid factor and positive serum for anti-nuclear antibodies, influenza A, and influenza B were observed. Moreover, the lateral flow kit remained stable after storage for 30 days at 37 °C. Our results demonstrate that the selenium nanoparticle lateral flow kit can conveniently, rapidly, and sensitively detect anti-SARS-CoV-2 IgM and IgG in human serum and blood; it can also be suitable for the epidemiological investigation of COVID-19.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/immunology , Clinical Laboratory Techniques , Coronavirus Infections/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Pneumonia, Viral/blood , Antibodies, Viral/immunology , COVID-19 , COVID-19 Testing , Coronavirus Infections/diagnosis , Coronavirus Infections/immunology , Equipment Design , HEK293 Cells , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Lab-On-A-Chip Devices , Limit of Detection , Nanoparticles/chemistry , Pandemics , Pneumonia, Viral/immunology , Point-of-Care Testing , Reagent Strips/analysis , SARS-CoV-2 , Selenium/chemistry
5.
Biosens Bioelectron ; 165: 112349, 2020 Oct 01.
Article in English | MEDLINE | ID: covidwho-459213

ABSTRACT

Timely detection and diagnosis are urgently needed to guide epidemiological measures, infection control, antiviral treatment, and vaccine research. In this review, biomarkers/indicators for diagnosis of coronavirus disease 2019 (COVID-19) or detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the environment are summarized and discussed. It is concluded that the detection methods targeting antibodies are not suitable for screening of early and asymptomatic cases since most patients had an antibody response at about 10 days after onset of symptoms. However, antibody detection methods can be combined with quantitative real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) to significantly improve the sensitivity and specificity of diagnosis, and boost vaccine research. Fast, sensitive and accurate detection methods targeting antigens need to be developed urgently. Various specimens for diagnosis or detection are compared and analyzed. Among them, deep throat saliva and induced sputum are desired for RT-qPCR test or other early detection technologies. Chest computerized tomography (CT) scan, RT-qPCR, lateral flow immunochromatographic strip (LFICS) for diagnosis of COVID-19 are summarized and compared. Specially, potential electrochemical (EC) biosensor, surface enhanced Raman scattering (SERS)-based biosensor, field-effect transistor (FET)-based biosensor, surface plasmon resonance (SPR)-based biosensor and artificial intelligence (AI) assisted diagnosis of COVID-19 are emphasized. Finally, some commercialized portable detection device, current challenges and future directions are discussed.


Subject(s)
Betacoronavirus/isolation & purification , Biosensing Techniques/instrumentation , Coronavirus Infections/diagnosis , Pneumonia, Viral/diagnosis , Animals , Antibodies, Viral/analysis , Antigens, Viral/analysis , Biosensing Techniques/methods , COVID-19 , Chromatography, Affinity/instrumentation , Chromatography, Affinity/methods , Environmental Monitoring/instrumentation , Environmental Monitoring/methods , Equipment Design , Humans , Pandemics , Polymerase Chain Reaction/instrumentation , Polymerase Chain Reaction/methods , RNA, Viral/analysis , Reagent Strips/analysis , SARS-CoV-2 , Tomography, X-Ray Computed/instrumentation , Tomography, X-Ray Computed/methods
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