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1.
Mikrochim Acta ; 188(10): 316, 2021 Sep 02.
Article in English | MEDLINE | ID: covidwho-1604245

ABSTRACT

A novel label-free surface plasmon resonance (SPR) aptasensor has been constructed for the detection of N-gene of SARS-CoV-2 by using thiol-modified niobium carbide MXene quantum dots (Nb2C-SH QDs) as the bioplatform for anchoring N-gene-targeted aptamer. In the presence of SARS-CoV-2 N-gene, the immobilized aptamer strands changed their conformation to specifically bind with N-gene. It thus increased the contact area or enlarged the distance between aptamer and the SPR chip, resulting in a change of the SPR signal irradiated by the laser (He-Ne) with the wavelength (λ) of 633 nm. Nb2C QDs were derived from Nb2C MXene nanosheets via a solvothermal method, followed by functionalization with octadecanethiol through a self-assembling method. Subsequently, the gold chip for SPR measurements was modified with Nb2C-SH QDs via covalent binding of the Au-S bond also by self-assembling interaction. Nb2C-SH QDs not only resulted in high bioaffinity toward aptamer but also enhanced the SPR response. Thus, the Nb2C-SH QD-based SPR aptasensor had low limit of detection (LOD) of 4.9 pg mL-1 toward N-gene within the concentration range 0.05 to 100 ng mL-1. The sensor also showed excellent selectivity in the presence of various respiratory viruses and proteins in human serum and high stability. Moreover, the Nb2C-SH QD-based SPR aptasensor displayed a vast practical application for the qualitative analysis of N-gene from different samples, including seawater, seafood, and human serum. Thus, this work can provide a deep insight into the construction of the aptasensor for detecting SARS-CoV-2 in complex environments. A novel label-free surface plasmon resonance aptasensor has been constructed to detect sensitively and selectively the N-gene of SARS-CoV-2 by using thiol-modified niobium carbide MXene quantum dots as the scaffold to anchor the N-gene-targeted aptamer.


Subject(s)
Aptamers, Nucleotide , COVID-19/diagnosis , Niobium/chemistry , Nucleocapsid/metabolism , Quantum Dots/chemistry , SARS-CoV-2/isolation & purification , Surface Plasmon Resonance/methods , COVID-19/virology , Humans , Limit of Detection
2.
J Nanobiotechnology ; 20(1): 6, 2022 Jan 04.
Article in English | MEDLINE | ID: covidwho-1608546

ABSTRACT

BACKGROUND: Gold nanoparticles (AuNPs) have been widely used in local surface plasmon resonance (LSPR) immunoassays for biomolecule sensing, which is primarily based on two conventional methods: absorption spectra analysis and colorimetry. The low figure of merit (FoM) of the LSPR and high-concentration AuNP requirement restrict their limit of detection (LOD), which is approximately ng to µg mL-1 in antibody detection if there is no other signal or analyte amplification. Improvements in sensitivity have been slow in recent for a long time, and pushing the boundary of the current LOD is a great challenge of current LSPR immunoassays in biosensing. RESULTS: In this work, we developed spectral image contrast-based flow digital nanoplasmon-metry (Flow DiNM) to push the LOD boundary. Comparing the scattering image brightness of AuNPs in two neighboring wavelength bands near the LSPR peak, the peak shift signal is strongly amplified and quickly detected. Introducing digital analysis, the Flow DiNM provides an ultrahigh signal-to-noise ratio and has a lower sample volume requirement. Compared to the conventional analog LSPR immunoassay, Flow DiNM for anti-BSA detection in pure samples has an LOD as low as 1 pg mL-1 within only a 15-min detection time and 500 µL sample volume. Antibody assays against spike proteins of SARS-CoV-2 in artificial saliva that contained various proteins were also conducted to validate the detection of Flow DiNM in complicated samples. Flow DiNM shows significant discrimination in detection with an LOD of 10 pg mL-1 and a broad dynamic detection range of five orders of magnitude. CONCLUSION: Together with the quick readout time and simple operation, this work clearly demonstrated the high sensitivity and selectivity of the developed Flow DiNM in rapid antibody detection. Spectral image contrast and digital analysis further provide a new generation of LSPR immunoassay with AuNPs.


Subject(s)
COVID-19 Serological Testing/methods , COVID-19/diagnosis , SARS-CoV-2/isolation & purification , Surface Plasmon Resonance/methods , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19 Serological Testing/instrumentation , Equipment Design , Gold/chemistry , Humans , Immunoassay/instrumentation , Immunoassay/methods , Metal Nanoparticles/chemistry , SARS-CoV-2/immunology , Saliva/virology , Spike Glycoprotein, Coronavirus/immunology , Surface Plasmon Resonance/instrumentation
3.
Front Biosci (Landmark Ed) ; 26(10): 789-798, 2021 10 30.
Article in English | MEDLINE | ID: covidwho-1498508

ABSTRACT

Background: The coronavirus disease 2019 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected more than 210 million individuals globally and resulted in over 4 million deaths since the first report in December 2019. The early use of traditional Chinese medicine (TCM) for light and ordinary patients, can rapidly improve symptoms, shorten hospitalization days and reduce severe cases transformed from light and normal. Many TCM formulas and products have a wide application in treating infectious and non-infectious diseases. Polygonum cuspidatum Sieb. et Zucc. (P. cuspidatum), is an important Traditional Chinese Medicine with actions of clearing away heat and eliminating dampness, draining the gallbladder to relieve jaundice, removing blood stasis to alleviate pain, resolving phlegm and arrest cough. In the search for anti-SARS-CoV-2, P. cuspidatum was recommended as as a therapeutic drug of COVID-19 pneumonia.In this study, we aimed to identifies P. cuspidatum is the potential broad-spectrum inhibitor for the treatment of coronaviruses infections. Methods: In the present study , we infected human malignant embryonal rhabdomyoma (RD) cells with the OC43 strain of the coronavirus, which represent an alternative model for SARS-CoV-2 and then employed the cell viability assay kit for the antiviral activity. We combined computer aided virtual screening to predicte the binding site and employed Surface plasmon resonance analysis (SPR) to comfirm the interaction between drugs and coronavirus. We employed fluorescence resonance energy transfer technology to identify drug's inhibition in the proteolytic activity of 3CLpro and Plpro. Results: Based on our results, polydatin and resveratrol derived from P. cuspidatum significantly suppressed HCoV-OC43 replication. 50% inhibitory concentration (IC50) values of polydatin inhibited SARS-CoV-2 Mpro and Plpro, MERS Mpro and Plpro were 18.66, 125, 14.6 and 25.42 µm, respectively. IC50 values of resveratrol inhibited SARS-CoV-2 Mpro and Plpro, MERS Mpro and Plpro were 29.81 ,60.86, 16.35 and19.04 µM, respectively. Finally, SPR assay confirmed that polydatin and resveratrol had high affinity to SARS-CoV-2, SARS-CoV 3Clpro, MERS-CoV 3Clpro and PLpro protein. Conclusions: we identified the antiviral activity of flavonoids polydatin and resveratrol on RD cells. Polydatin and resveratrol were found to be specific and selective inhibitors for SARS-CoV-2, 3CLpro and PLpro, viral cysteine proteases. In summary, this study identifies P. cuspidatum as the potential broad-spectrum inhibitor for the treatment of coronaviruses infections.


Subject(s)
Drugs, Chinese Herbal/chemistry , Fallopia japonica/chemistry , Glucosides/pharmacology , Resveratrol/pharmacology , SARS-CoV-2/drug effects , Stilbenes/pharmacology , Virus Replication/drug effects , Antiviral Agents/pharmacology , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19/virology , Cell Line, Tumor , Cell Survival/drug effects , Glucosides/metabolism , HEK293 Cells , Host-Pathogen Interactions/drug effects , Humans , Medicine, Chinese Traditional/methods , Pandemics , Protein Binding , Resveratrol/metabolism , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Stilbenes/metabolism , Surface Plasmon Resonance/methods , Viral Proteins/metabolism
4.
Biosensors (Basel) ; 11(8)2021 Jul 26.
Article in English | MEDLINE | ID: covidwho-1354921

ABSTRACT

The global damage that a widespread viral infection can cause is evident from the ongoing COVID-19 pandemic. The importance of virus detection to prevent the spread of viruses has been reaffirmed by the pandemic and the associated social and economic damage. Surface plasmon resonance (SPR) in microscale and localized SPR (LSPR) in nanoscale virus sensing systems are thought to be useful as next-generation detection methods. Many studies have been conducted on ultra-sensitive technologies, especially those based on signal amplification. In some cases, it has been reported that even a low viral load can be measured, indicating that the virus can be detected in patients even in the early stages of the viral infection. These findings corroborate that SPR and LSPR are effective in minimizing false-positives and false-negatives that are prevalent in the existing virus detection techniques. In this review, the methods and signal responses of SPR and LSPR-based virus detection technologies are summarized. Furthermore, this review surveys some of the recent developments reported and discusses the limitations of SPR and LSPR-based virus detection as the next-generation detection technologies.


Subject(s)
Metal Nanoparticles/chemistry , SARS-CoV-2/physiology , Surface Plasmon Resonance/methods , Virion/isolation & purification , COVID-19/diagnosis , COVID-19/virology , Dengue Virus/isolation & purification , Dengue Virus/physiology , Humans , Limit of Detection , Orthomyxoviridae/isolation & purification , Orthomyxoviridae/physiology , Point-of-Care Systems , SARS-CoV-2/isolation & purification , Virion/chemistry
5.
Biosensors (Basel) ; 11(8)2021 Jul 26.
Article in English | MEDLINE | ID: covidwho-1325599

ABSTRACT

Cell-based assays are a valuable tool for examination of virus-host cell interactions and drug discovery processes, allowing for a more physiological setting compared to biochemical assays. Despite the fact that cell-based SPR assays are label-free and thus provide all the associated benefits, they have never been used to study viral growth kinetics and to predict drug antiviral response in cells. In this study, we prove the concept that the cell-based SPR assay can be applied in the kinetic analysis of the early stages of viral infection of cells and the antiviral drug activity in the infected cells. For this purpose, cells immobilized on the SPR slides were infected with human coronavirus HCov-229E and treated with hydroxychloroquine. The SPR response was measured at different time intervals within the early stages of infection. Methyl Thiazolyl Tetrazolium (MTT) assay was used to provide the reference data. We found that the results of the SPR and MTT assays were consistent, and SPR is a reliable tool in investigating virus-host cell interaction and the mechanism of action of viral inhibitors. SPR assay was more sensitive and accurate in the first hours of infection within the first replication cycle, whereas the MTT assay was not so effective. After the second replication cycle, noise was generated by the destruction of the cell layer and by the remnants of dead cells, and masks useful SPR signals.


Subject(s)
Antiviral Agents/therapeutic use , Coronavirus 229E, Human/physiology , Coronavirus Infections/drug therapy , Hydroxychloroquine/therapeutic use , Surface Plasmon Resonance/methods , Animals , Antiviral Agents/pharmacology , Chlorocebus aethiops , Coronavirus 229E, Human/drug effects , Coronavirus 229E, Human/isolation & purification , Coronavirus Infections/pathology , Coronavirus Infections/virology , Humans , Hydroxychloroquine/pharmacology , Kinetics , Severity of Illness Index , Vero Cells
6.
Molecules ; 25(20)2020 Oct 13.
Article in English | MEDLINE | ID: covidwho-1305732

ABSTRACT

Nano-islands are entities (droplets or other shapes) that are formed by spontaneous dewetting (agglomeration, in the early literature) of thin and very thin metallic (especially gold) films on a substrate, done by post-deposition heating or by using other sources of energy. In addition to thermally generated nano-islands, more recently, nanoparticle films have also been dewetted, in order to form nano-islands. The localized surface plasmon resonance (LSPR) band of gold nano-islands was found to be sensitive to changes in the surrounding environment, making it a suitable platform for sensing and biosensing applications. In this review, we revisit the development of the concept of nano-island(s), the thermodynamics of dewetting of thin metal films, and the effect of the substrate on the morphology and optical properties of nano-islands. A special emphasis is made on nanoparticle films and their applications to biosensing, with ample examples from the authors' work.


Subject(s)
Gold/chemistry , Nanocomposites/chemistry , Point-of-Care Systems , Surface Plasmon Resonance/instrumentation , Animals , Biosensing Techniques/instrumentation , Growth Hormone/analysis , Humans , Lab-On-A-Chip Devices , Milk/chemistry , Nanotechnology/methods , Surface Plasmon Resonance/methods
7.
Anal Chem ; 93(2): 828-833, 2021 01 19.
Article in English | MEDLINE | ID: covidwho-1065763

ABSTRACT

A variety of surface plasmon resonance (SPR) sensing devices have been extensively used in biochemical detection for their characteristics of label-free, highly sensitive, and faster detecting. Among them, the spectrum-based SPR sensing devices have offered us great advantages in high-throughput sensing due to their large dynamic range and the possibility of detection resolution similar to that offered by angle interrogation. This paper demonstrates a spectrum-based SPR imaging sensing system with fast wavelength scanning capability achieved by an acousto-optic tunable filter (AOTF) and a low-cost and speckle-free halogen lamp implemented as the SPR excitation source. Especially, we developed a novel four-parameter-based spectral curve readjusting (4-PSCR) method for data processing, which offered us a faster and more accurate spectral data curve fitting process than the traditional polynomial fitting method. With the configuration, we have also conducted an SPR high-throughput detection of the novel coronavirus (COVID-19) spike protein, proving its application possibility in the screening of COVID-19 with high accuracy. We believe that the higher sensitivity and accuracy of the system have made it readily used in biochemical imaging and detecting applications.


Subject(s)
Spike Glycoprotein, Coronavirus/analysis , Surface Plasmon Resonance/methods , Algorithms , COVID-19/diagnosis , COVID-19/virology , Humans , Limit of Detection , Optics and Photonics , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Surface Plasmon Resonance/instrumentation , Temperature
8.
Molecules ; 26(1)2020 Dec 24.
Article in English | MEDLINE | ID: covidwho-1044927

ABSTRACT

The novel coronavirus disease (2019-nCoV) has been affecting global health since the end of 2019, and there is no sign that the epidemic is abating. Targeting the interaction between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein and the human angiotensin-converting enzyme 2 (ACE2) receptor is a promising therapeutic strategy. In this study, surface plasmon resonance (SPR) was used as the primary method to screen a library of 960 compounds. A compound 02B05 (demethylzeylasteral, CAS number: 107316-88-1) that had high affinities for S-RBD and ACE2 was discovered, and binding affinities (KD, µM) of 02B05-ACE2 and 02B05-S-RBD were 1.736 and 1.039 µM, respectively. The results of a competition experiment showed that 02B05 could effectively block the binding of S-RBD to ACE2 protein. Furthermore, pseudovirus infection assay revealed that 02B05 could inhibit entry of SARS-CoV-2 pseudovirus into 293T cells to a certain extent at nontoxic concentration. The compoundobtained in this study serve as references for the design of drugs which have potential in the treatment of COVID-19 and can thus accelerate the process of developing effective drugs to treat SARS-CoV-2 infections.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Protein Interaction Domains and Motifs/drug effects , SARS-CoV-2/metabolism , Surface Plasmon Resonance/methods , Triterpenes/pharmacology , Viral Proteins/metabolism , HEK293 Cells , Humans , Protein Binding
9.
Commun Biol ; 4(1): 70, 2021 01 15.
Article in English | MEDLINE | ID: covidwho-1033621

ABSTRACT

The proliferation and transmission of viruses has become a threat to worldwide biosecurity, as exemplified by the current COVID-19 pandemic. Early diagnosis of viral infection and disease control have always been critical. Virus detection can be achieved based on various plasmonic phenomena, including propagating surface plasmon resonance (SPR), localized SPR, surface-enhanced Raman scattering, surface-enhanced fluorescence and surface-enhanced infrared absorption spectroscopy. The present review covers all available information on plasmonic-based virus detection, and collected data on these sensors based on several parameters. These data will assist the audience in advancing research and development of a new generation of versatile virus biosensors.


Subject(s)
COVID-19/diagnosis , COVID-19/epidemiology , Pandemics , SARS-CoV-2/chemistry , Spectrum Analysis, Raman/methods , Surface Plasmon Resonance/methods , COVID-19/virology , Humans , Nanostructures/chemistry , Spectrometry, Fluorescence/methods , Spectrophotometry, Infrared/methods
10.
Anal Chem ; 93(2): 828-833, 2021 01 19.
Article in English | MEDLINE | ID: covidwho-977246

ABSTRACT

A variety of surface plasmon resonance (SPR) sensing devices have been extensively used in biochemical detection for their characteristics of label-free, highly sensitive, and faster detecting. Among them, the spectrum-based SPR sensing devices have offered us great advantages in high-throughput sensing due to their large dynamic range and the possibility of detection resolution similar to that offered by angle interrogation. This paper demonstrates a spectrum-based SPR imaging sensing system with fast wavelength scanning capability achieved by an acousto-optic tunable filter (AOTF) and a low-cost and speckle-free halogen lamp implemented as the SPR excitation source. Especially, we developed a novel four-parameter-based spectral curve readjusting (4-PSCR) method for data processing, which offered us a faster and more accurate spectral data curve fitting process than the traditional polynomial fitting method. With the configuration, we have also conducted an SPR high-throughput detection of the novel coronavirus (COVID-19) spike protein, proving its application possibility in the screening of COVID-19 with high accuracy. We believe that the higher sensitivity and accuracy of the system have made it readily used in biochemical imaging and detecting applications.


Subject(s)
Spike Glycoprotein, Coronavirus/analysis , Surface Plasmon Resonance/methods , Algorithms , COVID-19/diagnosis , COVID-19/virology , Humans , Limit of Detection , Optics and Photonics , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Surface Plasmon Resonance/instrumentation , Temperature
11.
J Biol Chem ; 295(52): 18579-18588, 2020 12 25.
Article in English | MEDLINE | ID: covidwho-894463

ABSTRACT

The novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has emerged to a pandemic and caused global public health crisis. Human angiotensin-converting enzyme 2(ACE2) was identified as the entry receptor for SARS-CoV-2. As a carboxypeptidase, ACE2 cleaves many biological substrates besides angiotensin II to control vasodilatation and vascular permeability. Given the nanomolar high affinity between ACE2 and SARS-CoV-2 spike protein, we investigated how this interaction would affect the enzymatic activity of ACE2. Surprisingly, SARS-CoV-2 trimeric spike protein increased ACE2 proteolytic activity ∼3-10 fold against model peptide substrates, such as caspase-1 substrate and Bradykinin-analog. The enhancement in ACE2 enzymatic function was mediated by the binding of SARS-CoV-2 spike RBD domain. These results highlighted the potential for SARS-CoV-2 infection to enhance ACE2 activity, which may be relevant to the cardiovascular symptoms associated with COVID-19.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , COVID-19/enzymology , COVID-19/virology , Humans , Protein Binding , Protein Domains , Proteolysis , Surface Plasmon Resonance/methods
12.
Sensors (Basel) ; 20(17)2020 Aug 22.
Article in English | MEDLINE | ID: covidwho-727442

ABSTRACT

The global burden of coronavirus disease 2019 (COVID-19) to public health and global economy has stressed the need for rapid and simple diagnostic methods. From this perspective, plasmonic-based biosensing can manage the threat of infectious diseases by providing timely virus monitoring. In recent years, many plasmonics' platforms have embraced the challenge of offering on-site strategies to complement traditional diagnostic methods relying on the polymerase chain reaction (PCR) and enzyme-linked immunosorbent assays (ELISA). This review compiled recent progress on the development of novel plasmonic sensing schemes for the effective control of virus-related diseases. A special focus was set on the utilization of plasmonic nanostructures in combination with other detection formats involving colorimetric, fluorescence, luminescence, or Raman scattering enhancement. The quantification of different viruses (e.g., hepatitis virus, influenza virus, norovirus, dengue virus, Ebola virus, Zika virus) with particular attention to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was reviewed from the perspective of the biomarker and the biological receptor immobilized on the sensor chip. Technological limitations including selectivity, stability, and monitoring in biological matrices were also reviewed for different plasmonic-sensing approaches.


Subject(s)
Betacoronavirus/isolation & purification , Biosensing Techniques , Coronavirus Infections/diagnosis , Pneumonia, Viral/diagnosis , Surface Plasmon Resonance/methods , Betacoronavirus/pathogenicity , COVID-19 , Colorimetry , Coronavirus Infections/virology , Fluorescence , Humans , Nanostructures/chemistry , Pandemics , Pneumonia, Viral/virology , SARS-CoV-2 , Spectrum Analysis, Raman
13.
ACS Sens ; 5(9): 2663-2678, 2020 09 25.
Article in English | MEDLINE | ID: covidwho-714278

ABSTRACT

The global sanitary crisis caused by the emergence of the respiratory virus SARS-CoV-2 and the COVID-19 outbreak has revealed the urgent need for rapid, accurate, and affordable diagnostic tests to broadly and massively monitor the population in order to properly manage and control the spread of the pandemic. Current diagnostic techniques essentially rely on polymerase chain reaction (PCR) tests, which provide the required sensitivity and specificity. However, its relatively long time-to-result, including sample transport to a specialized laboratory, delays massive detection. Rapid lateral flow tests (both antigen and serological tests) are a remarkable alternative for rapid point-of-care diagnostics, but they exhibit critical limitations as they do not always achieve the required sensitivity for reliable diagnostics and surveillance. Next-generation diagnostic tools capable of overcoming all the above limitations are in demand, and optical biosensors are an excellent option to surpass such critical issues. Label-free nanophotonic biosensors offer high sensitivity and operational robustness with an enormous potential for integration in compact autonomous devices to be delivered out-of-the-lab at the point-of-care (POC). Taking the current COVID-19 pandemic as a critical case scenario, we provide an overview of the diagnostic techniques for respiratory viruses and analyze how nanophotonic biosensors can contribute to improving such diagnostics. We review the ongoing published work using this biosensor technology for intact virus detection, nucleic acid detection or serological tests, and the key factors for bringing nanophotonic POC biosensors to accurate and effective COVID-19 diagnosis on the short term.


Subject(s)
Betacoronavirus , Coronavirus Infections/diagnosis , Nanostructures/chemistry , Pneumonia, Viral/diagnosis , Surface Plasmon Resonance/methods , Antigens, Viral/analysis , Betacoronavirus/chemistry , Betacoronavirus/isolation & purification , COVID-19 , COVID-19 Testing , Clinical Laboratory Techniques , Genome, Viral , Humans , Immunoassay/methods , Nanostructures/radiation effects , Pandemics , SARS-CoV-2 , Serologic Tests/methods
14.
ACS Nano ; 14(6): 7617-7627, 2020 06 23.
Article in English | MEDLINE | ID: covidwho-647565

ABSTRACT

The current outbreak of the pandemic coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) demands its rapid, convenient, and large-scale diagnosis to downregulate its spread within as well as across the communities. But the reliability, reproducibility, and selectivity of majority of such diagnostic tests fail when they are tested either to a viral load at its early representation or to a viral gene mutated during its current spread. In this regard, a selective "naked-eye" detection of SARS-CoV-2 is highly desirable, which can be tested without accessing any advanced instrumental techniques. We herein report the development of a colorimetric assay based on gold nanoparticles (AuNPs), when capped with suitably designed thiol-modified antisense oligonucleotides (ASOs) specific for N-gene (nucleocapsid phosphoprotein) of SARS-CoV-2, could be used for diagnosing positive COVID-19 cases within 10 min from the isolated RNA samples. The thiol-modified ASO-capped AuNPs agglomerate selectively in the presence of its target RNA sequence of SARS-CoV-2 and demonstrate a change in its surface plasmon resonance. Further, the addition of RNaseH cleaves the RNA strand from the RNA-DNA hybrid leading to a visually detectable precipitate from the solution mediated by the additional agglomeration among the AuNPs. The selectivity of the assay has been monitored in the presence of MERS-CoV viral RNA with a limit of detection of 0.18 ng/µL of RNA having SARS-CoV-2 viral load. Thus, the current study reports a selective and visual "naked-eye" detection of COVID-19 causative virus, SARS-CoV-2, without the requirement of any sophisticated instrumental techniques.


Subject(s)
Betacoronavirus/genetics , Biosensing Techniques/methods , Coronavirus Infections/diagnosis , Metal Nanoparticles , Nucleocapsid Proteins/genetics , Oligonucleotides, Antisense/genetics , Pneumonia, Viral/diagnosis , Base Sequence , Betacoronavirus/isolation & purification , COVID-19 , Colorimetry/methods , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , Coronavirus Nucleocapsid Proteins , Genes, Viral , Gold , Humans , Metal Nanoparticles/ultrastructure , Microscopy, Electron, Transmission , Nanotechnology/methods , Pandemics , Phosphoproteins , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , RNA Caps/genetics , RNA, Viral/genetics , SARS-CoV-2 , Surface Plasmon Resonance/methods
15.
ACS Nano ; 14(5): 5268-5277, 2020 May 26.
Article in English | MEDLINE | ID: covidwho-46728

ABSTRACT

The ongoing outbreak of the novel coronavirus disease (COVID-19) has spread globally and poses a threat to public health in more than 200 countries. Reliable laboratory diagnosis of the disease has been one of the foremost priorities for promoting public health interventions. The routinely used reverse transcription polymerase chain reaction (RT-PCR) is currently the reference method for COVID-19 diagnosis. However, it also reported a number of false-positive or -negative cases, especially in the early stages of the novel virus outbreak. In this work, a dual-functional plasmonic biosensor combining the plasmonic photothermal (PPT) effect and localized surface plasmon resonance (LSPR) sensing transduction provides an alternative and promising solution for the clinical COVID-19 diagnosis. The two-dimensional gold nanoislands (AuNIs) functionalized with complementary DNA receptors can perform a sensitive detection of the selected sequences from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through nucleic acid hybridization. For better sensing performance, the thermoplasmonic heat is generated on the same AuNIs chip when illuminated at their plasmonic resonance frequency. The localized PPT heat is capable to elevate the in situ hybridization temperature and facilitate the accurate discrimination of two similar gene sequences. Our dual-functional LSPR biosensor exhibits a high sensitivity toward the selected SARS-CoV-2 sequences with a lower detection limit down to the concentration of 0.22 pM and allows precise detection of the specific target in a multigene mixture. This study gains insight into the thermoplasmonic enhancement and its applicability in the nucleic acid tests and viral disease diagnosis.


Subject(s)
Betacoronavirus/chemistry , Biosensing Techniques/methods , Surface Plasmon Resonance/methods , Betacoronavirus/genetics , Biosensing Techniques/instrumentation , Biosensing Techniques/standards , DNA, Complementary/chemistry , DNA, Complementary/genetics , Gold/chemistry , Hot Temperature , Metal Nanoparticles/chemistry , Nucleic Acid Hybridization/methods , SARS-CoV-2 , Surface Plasmon Resonance/instrumentation , Surface Plasmon Resonance/standards
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