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1.
Microchem J ; 179: 107585, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-1946066

ABSTRACT

Currently, the development of biosensors is an urgent need due to the rapid spread of SARS-CoV-2 and the limitations of current standard methods for the diagnosis of COVID-19. Hence, many researchers have focused on the design of high-performance biosensors for measuring coronavirus genes. In this study, a voltammetric genosensor was developed for the determination of SARS-CoV-2 RdRP gene based on the format of cDNA probe/Au@CD core-shell NPs/graphite nanocrystals (GNCs)/paper electrode. For the first time, graphite nanocrystals were used in the electrochemical biosensor design. This genosensor was exposed to different concentrations of virus gene and then the hybridization between cDNA probe and RdRP gene was monitored by redox-active toluidine blue (TB). With increasing the RdRP concentration, the reduction peak current of TB enhanced in a linear range of 0.50 pM-12.00 nM according to the regression equation of I (µA) = 7.60 log CRdRP (pM) + 25.78. The repeatability with a RSD of 2.2% clearly exhibited that the response of modified electrode is stable because of the high adhesion of GNC layer on the paper substrate and the high stability of cDNA-Au@CD bioconjugates. The spike-and-recovery studies showed the acceptable recoveries for the sputum samples (>95%).

2.
Trends Analyt Chem ; 155: 116686, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-1895467

ABSTRACT

Viral infections are responsible for the deaths of millions of people throughout the world. Since outbreak of highly contagious and mutant viruses such as contemporary sars-cov-2 pandemic, has challenged the conventional diagnostic methods, the entity of a thoroughly sensitive, specific, rapid and inexpensive detecting technique with minimum level of false-positivity or -negativity, is desperately needed more than any time in the past decades. Biosensors as minimized devices could detect viruses in simple formats. So far, various nucleic acid, immune- and protein-based biosensors were designed and tested for recognizing the genome, antigen, or protein level of viruses, respectively; however, nucleic acid-based sensing techniques, which is the foundation of constructing genosensors, are preferred not only because of their ultra-sensitivity and applicability in the early stages of infections but also for their ability to differentiate various strains of the same virus. To date, the review articles related to genosensors are just confined to particular pathogenic diseases; In this regard, the present review covers comprehensive information of the research progress of the electrochemical, optical, and surface plasmon resonance (SPR) genosensors that applied for human viruses' diseases detection and also provides a well description of viruses' clinical importance, the conventional diagnosis approaches of viruses and their disadvantages. This review would address the limitations in the current developments as well as the future challenges involved in the successful construction of sensing approaches with the functionalized nanomaterials and also allow exploring into core-research works regarding this area.

3.
Chemistryselect ; 7(21):24, 2022.
Article in English | Web of Science | ID: covidwho-1885452

ABSTRACT

Zoonotic infections belong to multiple infectious diseases transferred from animals to humans. Now, the treatment and diagnosis of zoonotic infections are perplexing due to genetic mutations, target site modifications, and multi-drug resistance. Despite their benefits, most diagnostic molecular techniques have certain limits in terms of repeatability and sensitivity, mainly due to the heterogeneity among the diverse family of zoonotic pathogens. Therefore, developing more efficient and cost-effective theranostics tools is the need of the hour to address these concerns. For this purpose, nanotechnology has revolutionized medicine with versatile potential capabilities for diagnosing and treating zoonosis via the targeted and controlled delivery of antimicrobial drugs via binding to the overexpressed infectious macrophages. Massive advancements have been made in fabricating novel nano-based formulations to control zoonosis based on the use of poly(ethylenimine)-conjugated nanomicelles, mannosylated thiolated chitosan (MTC)-coated PM-loaded PLGA NPs, mannose linked thiolated nanocarriers, adjuvanted pDNA hydrogel, arginine-based nanocarriers, quantum dots to treat and diagnose a wide range of zoonotic diseases, including zoonotic influenza, salmonellosis, leishmaniasis, rabies, brucellosis, Lyme Disease, tuberculosis, and other infections caused by West Nile Virus, emerging coronaviruses (SARS, MERS, COVID-19), in a preferentially targeted way. Recently developed anti-pathogen loaded-nanoformulations with enhanced cellular uptake, biocompatibility, and hemocompatibility have shown the ability to cross biological barriers when orally administrated. Therefore, this article reviewed the latest milestones and future growth areas in the field of efficient theranostics platforms to manage zoonotic infections.

4.
Talanta ; 245: 123482, 2022 Aug 01.
Article in English | MEDLINE | ID: covidwho-1796082

ABSTRACT

Infection caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is responsible for the Coronavirus disease (COVID-19) and the current pandemic. Its mortality rate increases, demonstrating the imperative need for acute and rapid diagnostic tools as an alternative to current serological tests and molecular techniques. Features of electrochemical genosensor devices make them amenable for fast and accurate testing closer to the patient. This work reports on a specific electrochemical genosensor for SARS-CoV-2 detection and discrimination against homologous respiratory viruses. The electrochemical biosensor was assembled by immobilizing thiolated capture probes on top of maleimide-coated magnetic particles, followed by specific target hybridization between the capture and biotinylated signaling probes in a sandwich-type manner. The probes were rigorously designed bioinformatically and tested in vitro. Enzymatic complexes based on streptavidin-horseradish peroxidase linked the biotinylated signaling probe to render the biosensor electrochemical response. The genosensor showed to reach a sensitivity of 174.4 µA fM-1 and a limit of detection of 807 fM when using streptavidin poly-HRP20 enzymatic complex, detected SARS-CoV-2 specifically and discriminated it against homologous viruses in spiked samples and samples from SARS-CoV-2 cell cultures, a step forward to detect SARS-CoV-2 closer to the patient as a promising way for diagnosis and surveillance of COVID-19.


Subject(s)
Biosensing Techniques , COVID-19 , Biosensing Techniques/methods , COVID-19/diagnosis , Electrochemical Techniques/methods , Humans , Pandemics , SARS-CoV-2/genetics , Streptavidin
5.
FlatChem ; : 100336, 2022.
Article in English | ScienceDirect | ID: covidwho-1620663

ABSTRACT

Discovered in December 2019, the Severe Acute Respiratory Syndrome Coronavirus 2 (aka SARS-CoV-2 or 2019-nCoV) has attracted worldwide attention and concerns due to its high transmissibility and the severe health consequences experienced upon its infection, particularly by elderly people. Over 272 million people have been infected till date and over 5.33 million people could not survive the respiratory illness known as COVID-19 syndrome. Rapid and low-cost detection methods are of utmost importance to monitor the diffusion of the virus and to aid in the global fight against the pandemic. We propose here the use of graphene oxide nanocolloids (GONC) as an electroactive nanocarbon material that can act simultaneously as a transducing platform as well as the electroactive label for the detection of 2019-nCoV genomic sequences. The ability of GONC to provide an intrinsic electrochemical signal arising from the reduction of the electrochemically reducible oxygen functionalities present on its surface, allows GONC to be used as a simple and sensitive biosensing platform. Different intrinsic electroactivity of the material was obtained at each step of the genosensing process, starting from the immobilization of a short-stranded DNA probe and followed by the incubation with different concentrations of the target 2019-nCoV DNA strand. Monitoring such variations enabled the quantification of the target analyte over a wide dynamic range between 10−10 and 10−5 M. All in all, this proof-of-concept system serves as a stepping stone for the development of a rapid, sensitive and selective analytical tool for the detection of 2019-nCoV as well as other similar viral vectors. The use of cost-effective electrochemical detection methods coupled with the vast availability and suitability of carbon-based nanomaterials make this sensing system a valid candidate for low-cost and point-of-care analysis.

6.
Anal Chim Acta ; 1159: 338384, 2021 May 15.
Article in English | MEDLINE | ID: covidwho-1279519

ABSTRACT

Viruses are the causing agents for many relevant diseases, including influenza, Ebola, HIV/AIDS, and COVID-19. Its rapid replication and high transmissibility can lead to serious consequences not only to the individual but also to collective health, causing deep economic impacts. In this scenario, diagnosis tools are of significant importance, allowing the rapid, precise, and low-cost testing of a substantial number of individuals. Currently, PCR-based techniques are the gold standard for the diagnosis of viral diseases. Although these allow the diagnosis of different illnesses with high precision, they still present significant drawbacks. Their main disadvantages include long periods for obtaining results and the need for specialized professionals and equipment, requiring the tests to be performed in research centers. In this scenario, biosensors have been presented as promising alternatives for the rapid, precise, low-cost, and on-site diagnosis of viral diseases. This critical review article describes the advancements achieved in the last five years regarding electrochemical biosensors for the diagnosis of viral infections. First, genosensors and aptasensors for the detection of virus and the diagnosis of viral diseases are presented in detail regarding probe immobilization approaches, detection methods (label-free and sandwich), and amplification strategies. Following, immunosensors are highlighted, including many different construction strategies such as label-free, sandwich, competitive, and lateral-flow assays. Then, biosensors for the detection of viral-diseases-related biomarkers are presented and discussed, as well as point of care systems and their advantages when compared to traditional techniques. Last, the difficulties of commercializing electrochemical devices are critically discussed in conjunction with future trends such as lab-on-a-chip and flexible sensors.


Subject(s)
Biosensing Techniques , Electrochemical Techniques , Virus Diseases/diagnosis , Viruses/isolation & purification , Humans , Immunoassay
7.
Mikrochim Acta ; 188(4): 121, 2021 03 10.
Article in English | MEDLINE | ID: covidwho-1126559

ABSTRACT

A voltammetric genosensor has been developed for the early diagnosis of COVID-19 by determination of RNA-dependent RNA polymerase (RdRP) sequence as a specific target of novel coronavirus. The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) uses an RdRP for the replication of its genome and the transcription of its genes. Here, the silver ions (Ag+) in the hexathia-18-crown-6 (HT18C6) were used for the first time as a redox probe. Then, the HT18C6(Ag) incorporated carbon paste electrode (CPE) was further modified with chitosan and PAMAM dendrimer-coated silicon quantum dots (SiQDs@PAMAM) for immobilization of probe sequences (aminated oligonucleotides). The current intensity of differential pulse voltammetry using the redox probe was found to decrease with increasing the concentration of target sequence. Based on such signal-off trend, the proposed genosensor exhibited a good linear response to SARS-CoV-2 RdRP in the concentration range 1.0 pM-8.0 nM with a regression equation I (µA) = - 6.555 log [RdRP sequence] (pM) + 32.676 (R2 = 0.995) and a limit of detection (LOD) of 0.3 pM. The standard addition method with different spike concentrations of RdRP sequence in human sputum samples showed a good recovery for real sample analysis (> 95%). Therefore, the developed voltammetric genosensor can be used to determine SARS-CoV-2 RdRP sequence in sputum samples. PAMAM-functionalized SiQDs were used as a versatile electrochemical platform for the SARS-CoV-2 RdRP detection based on a signal off sensing strategy. In this study, for the first time, the silver ions (Ag+) in the hexathia-18-crown-6 carrier were applied as an electrochemical probe.


Subject(s)
COVID-19 Testing/instrumentation , Nanotechnology/methods , RNA-Dependent RNA Polymerase/genetics , SARS-CoV-2/genetics , Biosensing Techniques , Dendrimers , Early Diagnosis , Electrodes , Humans , Limit of Detection , Sputum/virology , Virus Replication/genetics
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