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1.
ACS Sens ; 9(6): 3158-3169, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38843447

RESUMO

An integrated approach combining surface-enhanced Raman spectroscopy (SERS) with a specialized deep learning algorithm to rapidly and accurately detect and quantify SARS-CoV-2 variants is developed based on an angiotensin-converting enzyme 2 (ACE2)-functionalized AgNR@SiO2 array SERS sensor. SERS spectra with concentrations of different variants were collected using a portable Raman system. After appropriate spectral preprocessing, a deep learning algorithm, CoVari, is developed to predict both the viral variant species and concentrations. Using a 10-fold cross-validation strategy, the model achieves an average accuracy of 99.9% in discriminating between different virus variants and R2 values larger than 0.98 for quantifying viral concentrations of the three viruses, demonstrating the high quality of the detection. The limit of detection of the ACE2 SERS sensor is determined to be 10.472, 11.882, and 21.591 PFU/mL for SARS-CoV-2, SARS-CoV-2 B1, and CoV-NL63, respectively. The feature importance of virus classification and concentration regression in the CoVari algorithm are calculated based on a permutation algorithm, which showed a clear correlation to the biochemical origins of the spectra or spectral changes. In an unknown specimen test, classification accuracy can achieve >90% for concentrations larger than 781 PFU/mL, and the predicted concentrations consistently align with actual values, highlighting the robustness of the proposed algorithm. Based on the CoVari architecture and the output vector, this algorithm can be generalized to predict both viral variant species and concentrations simultaneously for a broader range of viruses. These results demonstrate that the SERS + CoVari strategy has the potential for rapid and quantitative detection of virus variants and potentially point-of-care diagnostic platforms.


Assuntos
Enzima de Conversão de Angiotensina 2 , COVID-19 , Aprendizado Profundo , SARS-CoV-2 , Análise Espectral Raman , Análise Espectral Raman/métodos , SARS-CoV-2/isolamento & purificação , Humanos , COVID-19/diagnóstico , COVID-19/virologia , Enzima de Conversão de Angiotensina 2/metabolismo , Enzima de Conversão de Angiotensina 2/química , Nanopartículas Metálicas/química , Prata/química , Técnicas Biossensoriais/métodos , Dióxido de Silício/química , Algoritmos , Limite de Detecção
2.
Adv Sci (Weinh) ; 11(23): e2310066, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38634211

RESUMO

Simple, sensitive, and accurate molecular diagnostics are critical for preventing rapid spread of infection and initiating early treatment of diseases. However, current molecular detection methods typically rely on extensive nucleic acid sample preparation and expensive instrumentation. Here, a simple, fully integrated, lab-in-a-magnetofluidic tube (LIAMT) platform is presented for "sample-to-result" molecular detection of virus. By leveraging magnetofluidic transport of micro/nano magnetic beads, the LIAMT device integrates viral lysis, nucleic acid extraction, isothermal amplification, and CRISPR detection within a single engineered microcentrifuge tube. To enable point-of-care molecular diagnostics, a palm-sized processor is developed for magnetofluidic separation, nucleic acid amplification, and visual fluorescence detection. The LIAMT platform is applied to detect SARS-CoV-2 and HIV viruses, achieving a detection sensitivity of 73.4 and 63.9 copies µL-1, respectively. Its clinical utility is further demonstrated by detecting SARS-CoV-2 and HIV in clinical samples. This simple, affordable, and portable LIAMT platform holds promise for rapid and sensitive molecular diagnostics of infectious diseases at the point-of-care.


Assuntos
COVID-19 , Dispositivos Lab-On-A-Chip , Técnicas de Amplificação de Ácido Nucleico , SARS-CoV-2 , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Humanos , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , COVID-19/diagnóstico , COVID-19/virologia , Sistemas Automatizados de Assistência Junto ao Leito , Sensibilidade e Especificidade , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/instrumentação , Desenho de Equipamento , Infecções por HIV/diagnóstico , Infecções por HIV/virologia , HIV/genética , HIV/isolamento & purificação
3.
Environ Sci Technol ; 58(11): 4926-4936, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38452107

RESUMO

This study introduces a novel surface-enhanced Raman spectroscopy (SERS)-based lateral flow test (LFT) dipstick that integrates digital analysis for highly sensitive and rapid viral quantification. The SERS-LFT dipsticks, incorporating gold-silver core-shell nanoparticle probes, enable pixel-based digital analysis of large-area SERS scans. Such an approach enables ultralow-level detection of viruses that readily distinguishes positive signals from background noise at the pixel level. The developed digital SERS-LFTs demonstrate limits of detection (LODs) of 180 fg for SARS-CoV-2 spike protein, 120 fg for nucleocapsid protein, and 7 plaque forming units for intact virus, all within <30 min. Importantly, digital SERS-LFT methods maintain their robustness and their LODs in the presence of indoor dust, thus underscoring their potential for accurate and reliable virus diagnosis and quantification in real-world environmental settings.


Assuntos
Nanopartículas Metálicas , Glicoproteína da Espícula de Coronavírus , Vírus , Humanos , Análise Espectral Raman/métodos , Nanopartículas Metálicas/química , Limite de Detecção , Ouro/química
4.
Int J Biol Macromol ; 264(Pt 1): 130540, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38430998

RESUMO

Polypyrimidine sequences can be targeted by antiparallel clamps forming triplex structures either for biosensing or therapeutic purposes. Despite its successful implementation, their biophysical properties remain to be elusive. In this work, PAGE, circular dichroism and multivariate analysis were used to evaluate the properties of PPRHs directed to SARS-CoV-2 genome. Several PPRHs designed to target various polypyrimidine sites within the viral genome were synthesized. These PPRHs displayed varying binding affinities, influenced by factors such as the length of the PPRH and its GC content. The number and position of pyrimidine interruptions relative to the 4 T loop of the PPRH was found a critical factor, affecting the binding affinity with the corresponding target. Moreover, these factors also showed to affect in the intramolecular and intermolecular equilibria of PPRHs alone and when hybridized to their corresponding targets, highlighting the polymorphic nature of these systems. Finally, the functionality of the PPRHs was evaluated in a thermal lateral flow sensing device showing a good correspondence between their biophysical properties and detection limits. These comprehensive studies contribute to the understanding of the critical factors involved in the design of PPRHs for effective targeting of biologically relevant genomes through the formation of triplex structures under neutral conditions.

5.
Heliyon ; 10(3): e25377, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38322940

RESUMO

Molecular diagnostic methods to detect and quantify viral RNA in clinical samples rely on the purification of the genetic material prior to reverse transcription polymerase chain reaction (qRT-PCR). Due to the large number of samples processed in clinical laboratories, automation has become a necessity in order to increase method processivity and maximize throughput per unit of time. An attractive option for isolating viral RNA is based on the magnetic solid phase separation procedure (MSPS) using magnetic microparticles. This method offers the advantage over other alternative methods of making it possible to automate the process. In this study, we report the results of the MSPS method based on magnetic microparticles obtained by a simple synthesis process, to purify RNA from oro- and nasopharyngeal swab samples of patients suspected of COVID-19 provided by three diagnostic laboratories located in the Buenos Aires Province, Argentina. Magnetite nanoparticles of Fe3O4 (MNPs) were synthesized by the coprecipitation method and then coated with silica (SiO2) produced by hydrolysis of tetraethyl orthosilicate (TEOS). After preliminary tests on samples from the A549 human lung cell line and swabs, an extraction protocol was developed. The quantity and purity of the RNA obtained were determined by gel electrophoresis, spectrophotometry, and qRT-PCR. Tests on samples from naso- and oropharyngeal swabs were performed in order to validate the method for RNA purification in high-throughput SARS-CoV-2 diagnosis by qRT-PCR. The method was compared to the spin columns method and the automated method using commercial magnetic particles. The results show that the method developed is efficient for RNA extraction from nasal and oropharyngeal swab samples, and also comparable to other extraction methods in terms of sensitivity for SARS-CoV-2 detection. Of note, this procedure and reagents developed locally were intended to overcome the shortage of imported diagnostic supplies as the sudden spread of COVID-19 required unexpected quantities of nucleic acid isolation and diagnostic kits worldwide.

6.
Antibiotics (Basel) ; 12(12)2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38136758

RESUMO

The targeted or universal decolonization of patients through octenidine for nasal treatment and antiseptic body wash for 3 to 5 days prior elective surgery has been implemented in several surgical disciplines in order to significantly reduce surgical site infections (SSIs) caused by Staphylococcus aureus carriage. However, as most healthcare facilities also screen patients on admission for pilot infection, it is imperative that a prophylactic nasal decolonization procedure not yield a false negative SARS-CoV-2 status in otherwise positive patients. We assessed the effect of a commercially available octenidine-containing nasal gel on two different screening methods-antigen (Ag) detection based on colloidal gold immunochromatography and RT-PCR-in a prospective-type accuracy pilot study in asymptomatic SARS-CoV-2-positive inpatients. All patients still showed a positive test result after using the octenidine-containing nasal gel for about 3 days; therefore, its application did not influence SARS-CoV-2 screening, which is of high clinical relevance. Of note is that Ag detection was less sensitive, regardless of the presence of octenidine. From an infection prevention perspective, these results favor octenidine-based decolonization strategies, even during seasonal SARS-CoV-2 periods. As only asymptomatic patients are considered for elective interventions, screening programs based on RT-PCR technology should be preferred.

7.
Infection ; 51(6): 1809-1818, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37828369

RESUMO

PURPOSE AND METHODS: The emergence of coronavirus disease 2019 (COVID-19) has once again affirmed the significant threat of respiratory infections to global public health and the utmost importance of prompt diagnosis in managing and mitigating any pandemic. The nucleic acid amplification test (NAAT) is the primary detection method for most pathogens. Loop-mediated isothermal amplification (LAMP) is a rapid, simple, sensitive, and specific epitome of isothermal NAAT performed using a set of four to six primers. Primer design is a fundamental step in LAMP assays, with several complexities and experimental screening requirements. To address this challenge, an online database is presented here. Its workflow comprises three steps: literature aggregation, data curation, and database and website implementation. RESULTS: LAMPPrimerBank ( https://lampprimerbank.mathematik.uni-marburg.de ) is a manually curated database dedicated to experimentally validated LAMP primers, their peculiarities of assays, and accompanying literature, with a primary emphasis on respiratory pathogens. LAMPPrimerBank, with its user-friendly web interface and an open application programming interface, enables the accelerated and facile exploration, comparison, and exportation of LAMP primer sequences and their respective information from the massively scattered literature. LAMPPrimerBank currently comprises LAMP primers for diagnosing viral, bacterial, and fungal respiratory pathogens. Additionally, to address the challenge of false-positive results generated by nonspecific amplifications, LAMPPrimerBank computationally predicted and visualized the sizes of LAMP products for recorded primer sets in the database. CONCLUSION: LAMPPrimerBank, as a pioneering database in the rapidly expanding field of isothermal NAAT, endeavors to confront the two challenges of the LAMP: primer design and discrimination of false-positive results.


Assuntos
COVID-19 , Técnicas de Diagnóstico Molecular , Humanos , Sensibilidade e Especificidade , Técnicas de Diagnóstico Molecular/métodos , COVID-19/diagnóstico , Técnicas de Amplificação de Ácido Nucleico/métodos
9.
Nano Converg ; 10(1): 51, 2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37902883

RESUMO

Antibody sensor to detect viruses has been widely used but has problems such as the difficulty of right direction control of the receptor site on solid substrate, and long time and high cost for design and production of antibodies to new emerging viruses. The virus detection sensor with a recombinant protein embedded liposome (R/Li) was newly developed to solve the above problems, in which R/Li was assembled on AuNPs (Au@R/Li) to increase the sensitivity using localized surface plasmon resonance (LSPR) method. Recombinant angiotensin-converting enzyme-2 (ACE2) was used as host receptors of SARS-CoV and SARS-CoV-2, and the direction of enzyme active site for virus attachment could be controlled by the integration with liposome. The recombinant protein embedded liposomes were assembled on AuNPs, and LSPR method was used for detection. With the sensor platform S1 protein of both viruses was detected with detection limit of 10 pg/ml and SARS-CoV-2 in clinical samples was detected with 10 ~ 35 Ct values. In the selectivity test, MERS-CoV did not show a signal due to no binding with Au@R/Li. The proposed sensor platform can be used as promising detection method with high sensitivity and selectivity for the early and simple diagnosis of new emerging viruses.

10.
Microbiol Spectr ; 11(6): e0172323, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37861316

RESUMO

IMPORTANCE: Widespread and frequent testing for COVID-19 was an important strategy to identify infected patients to isolate and control the spread of the disease during the pandemic. The nasopharyngeal swab (NPS) global supply chain and access to trained healthcare professionals for standard NPS collection were often compromised. Patient discomfort and limited access challenged health systems to reach large numbers for testing in adult and pediatric populations. Our study revealed that swish and gargle saliva (SGS) was comparable to NPS in detecting SARS-CoV-2 and more patient-friendly than NPS. Patients were more likely to repeat the test with SGS. SGS was amenable to self-collection instead of relying on skilled professionals. This comprehensive evaluation highlights the challenges of comparing the accuracy of new methods to imperfect gold standards and identifies additional patient-centric factors that should be considered when defining such standards. Thus, SGS is an advantageous alternative specimen collection for outpatient en masse testing.


Assuntos
COVID-19 , SARS-CoV-2 , Adulto , Criança , Humanos , COVID-19/diagnóstico , Saliva , Teste para COVID-19 , Pacientes Ambulatoriais , Manejo de Espécimes/métodos , Nasofaringe
11.
Anal Chim Acta ; 1278: 341726, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37709467

RESUMO

The appearance of new viruses and diseases has made the development of rapid and reliable diagnostic tests crucial. In light of it, we proposed a new method for assembling an electrochemical immunosensor, based on a one-step approach for selective layer formation. For this purpose, a mixture containing the immobilizing agent (polyxydroxybutyrate, PHB) and the recognition element (antibodies against SARS-CoV-2 nucleocapsid protein) was prepared and used to modify a screen-printed carbon electrode with electrodeposited graphene oxide, for the detection of SARS-CoV-2 nucleocapsid protein (N-protein). Under optimum conditions, N-protein was successfully detected in three different matrixes - saliva, serum, and nasal swab, with the lowest detectable values of 50 pg mL-1, 1.0 ng mL-1, and 50 pg mL-1, respectively. Selectivity was assessed against SARS-CoV-2 receptor-binding domain protein (RBD) and antibodies against yellow fever (YF), and no significant response was observed in presence of interferents, reinforcing the suitability of the proposed one-step approach for selective layer formation. The proposed biosensor was stable for up to 14 days, and the mixture was suitable for immunosensor preparation even after 60 days of preparation. The proposed assembly strategy reduces the cost, analysis time, and waste generation. This reduction is achieved through miniaturization, which results in the decreased use of reagents and sample volumes. Additionally, this approach enables healthcare diagnostics to be conducted in developing regions with limited resources. Therefore, the proposed one-step approach for selective layer formation is a suitable, simpler, and a reliable alternative for electrochemical immunosensing.


Assuntos
Técnicas Biossensoriais , COVID-19 , Humanos , COVID-19/diagnóstico , Imunoensaio , SARS-CoV-2 , Anticorpos , Proteínas do Nucleocapsídeo
12.
Electrophoresis ; 44(19-20): 1579-1587, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37528696

RESUMO

RNA virus infection such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection shows severe respiratory symptoms on human and could be an obvious individual characteristic for investigations in forensic science. As for biological samples suspected to contain RNA virus in forensic casework, it requires respective detection of viral RNA and human DNA: reverse transcriptase polymerase chain reaction and DNA type (short tandem repeat [STR] analysis). Capillary electrophoresis (CE) has been shown to be a versatile technique and used for a variety of applications, so we preliminarily explored the co-detection of RNA virus and STR type on CE by developing a system of co-detecting SARS-CoV-2 and STR type under ensuring both the efficiency of forensic DNA analysis and safety of the laboratory. This study investigated the development and validation of the system, including N and ORF1ab primer designs, polymerase chain reaction amplification, allelic ladder, CE detection, thermal cycling parameters, concordance, sensitivity, species specificity, precision, and contrived and real SARS-CoV-2 sample studies. Final results showed the system could simultaneously detect SARS-CoV-2 and STR type, further indicating that CE has possibilities in the multi-detection of RNA viruses/STR type to help to prompt individual characteristics (viral infection) and narrow the scope of investigation in forensic science.


Assuntos
COVID-19 , Impressões Digitais de DNA , Humanos , Impressões Digitais de DNA/métodos , SARS-CoV-2/genética , DNA , Eletroforese Capilar , Repetições de Microssatélites
13.
Jpn Dent Sci Rev ; 2023 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-37360001

RESUMO

Accurate, self-collected, and non-invasive diagnostics are critical to perform mass-screening diagnostic tests for COVID-19. This systematic review with meta-analysis evaluated the accuracy, sensitivity, and specificity of salivary diagnostics for COVID-19 based on SARS-CoV-2 RNA compared with the current reference tests using a nasopharyngeal swab (NPS) and/or oropharyngeal swab (OPS). An electronic search was performed in seven databases to find COVID-19 diagnostic studies simultaneously using saliva and NPS/OPS tests to detect SARS-CoV-2 by RT-PCR. The search resulted in 10,902 records, of which 44 studies were considered eligible. The total sample consisted of 14,043 participants from 21 countries. The accuracy, specificity, and sensitivity for saliva compared with the NPS/OPS was 94.3% (95%CI= 92.1;95.9), 96.4% (95%CI= 96.1;96.7), and 89.2% (95%CI= 85.5;92.0), respectively. Besides, the sensitivity of NPS/OPS was 90.3% (95%CI= 86.4;93.2) and saliva was 86.4% (95%CI= 82.1;89.8) compared to the combination of saliva and NPS/OPS as the gold standard. These findings suggest a similarity in SARS-CoV-2 RNA detection between NPS/OPS swabs and saliva, and the association of both testing approaches as a reference standard can increase by 3.6% the SARS-CoV-2 detection compared with NPS/OPS alone. This study supports saliva as an attractive alternative for diagnostic platforms to provide a non-invasive detection of SARS-CoV-2.

14.
Biosens Bioelectron ; 236: 115421, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37244083

RESUMO

We developed a multi-pronged approach to enhance the detection sensitivity of localized surface plasmon resonance (LSPR) sensor chips to detect SARS-CoV-2. To this end, poly(amidoamine) dendrimers were immobilized onto the surface of LSPR sensor chips to serve as templates to further conjugate aptamers specific for SARS-CoV-2. The immobilized dendrimers were shown to reduce surface nonspecific adsorptions and increase capturing ligand density on the sensor chips, thereby improving detection sensitivity. To characterize the detection sensitivity of the surface-modified sensor chips, SARS-CoV-2 spike protein receptor-binding domain was detected using LSPR sensor chips with different surface modifications. The results showed that the dendrimer-aptamer modified LSPR sensor chip exhibited a limit of detection (LOD) of 21.9 pM, a sensitivity that was 9 times and 152 times more sensitive than the traditional aptamer- or antibody-based LSPR sensor chips, respectively. In addition, detection sensitivity was further improved by combining rolling circle amplification product and gold nanoparticles to further amplify the detection signals by increasing both the target mass and plasmonic coupling effects. Using pseudo SARS-CoV-2 viral particles as detection targets, we demonstrated that this combined signal intensification approach further enhanced the detection sensitivity by 10 folds with a remarkable LOD of 148 vp/mL, making it one of the most sensitive SARS-CoV-2 detection assays reported to date. These results highlight the potential of a novel LSPR-based detection platform for sensitive and rapid detection of COVID-19 infections, as well as other viral infections and point-of-care applications.


Assuntos
Técnicas Biossensoriais , COVID-19 , Dendrímeros , Nanopartículas Metálicas , Humanos , Ressonância de Plasmônio de Superfície/métodos , Técnicas Biossensoriais/métodos , Ouro/química , COVID-19/diagnóstico , Nanopartículas Metálicas/química , SARS-CoV-2
15.
ACS Sens ; 8(6): 2159-2168, 2023 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-37253267

RESUMO

In addition to efficacious vaccines and antiviral therapeutics, reliable and flexible in-home personal use diagnostics for the detection of viral antigens are needed for effective control of the COVID-19 pandemic. Despite the approval of several PCR-based and affinity-based in-home COVID-19 testing kits, many of them suffer from problems such as a high false-negative rate, long waiting time, and short storage period. Using the enabling one-bead-one-compound (OBOC) combinatorial technology, several peptidic ligands with a nanomolar binding affinity toward the SARS-CoV-2 spike protein (S-protein) were successfully discovered. Taking advantage of the high surface area of porous nanofibers, immobilization of these ligands on nanofibrous membranes allows the development of personal use sensors that can achieve low nanomolar sensitivity in the detection of the S-protein in saliva. This simple biosensor employing naked-eye reading exhibits detection sensitivity comparable to some of the current FDA-approved home detection kits. Furthermore, the ligand used in the biosensor was found to detect the S-protein derived from both the original strain and the Delta variant. The workflow reported here may enable us to rapidly respond to the development of home-based biosensors against future viral outbreaks.


Assuntos
Técnicas Biossensoriais , COVID-19 , Humanos , COVID-19/diagnóstico , Glicoproteína da Espícula de Coronavírus/química , SARS-CoV-2 , Ligantes , Teste para COVID-19 , Colorimetria , Pandemias , Peptídeos
16.
Biosensors (Basel) ; 13(4)2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-37185548

RESUMO

The SARS-CoV-2 worldwide outbreak prompted the development of several tools to detect and treat the disease. Among the new detection proposals, the use of peptides mimetics has surged as an alternative to avoid the use of antibodies, of which there has been a shortage during the COVID-19 pandemic. However, the use of peptides in detection systems still presents some questions to be answered, mainly referring to their stability under different environmental conditions. In this work, we synthesized an ACE2 peptide mimic and evaluated its stability in different pH, salinity, polarity, and temperature conditions. Further, the same conditions were assessed when using the ability of the peptide mimic to detect the recombinant SARS-CoV-2 spike protein in a biotin-streptavidin-enzyme-linked assay. Finally, we also tested the capacity of the peptide to detect SARS-CoV-2 from patients' samples. The results indicate that the peptide is structurally sensitive to the medium conditions, with relevance to the pH, where basic pH favored its performance when used as a SARS-CoV-2 detector. Further, the proposed peptide mimic was able to detect SARS-CoV-2 comparably to RT-qPCR results. Therefore, the present study promotes knowledge advancement, particularly in terms of stability considerations, in the application of peptide mimics as a replacement for antibodies in detection systems.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , SARS-CoV-2 , Enzima de Conversão de Angiotensina 2 , RNA Viral , Pandemias , Peptídeos , Ligação Proteica
17.
Anal Chim Acta ; 1260: 341207, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37121656

RESUMO

The state-of-the-art SARS-CoV-2 detection methods include qRT-PCR and antibody-based lateral flow assay (LFA) point-of-care tests. Despite the high sensitivity and selectivity, qRT-PCR is slow, expensive and needs well-trained operators. On the other extreme, LFA suffers from low sensitivity albeit its fast detection speed, low detection cost and ease of use. Therefore, the continuing COVID-19 pandemic calls for a SARS-CoV-2 detection method that is rapid, convenient and cost-effective without compromise in sensitivity. Here we provide a proof-of-principle demonstration of an optimized aptamer-based nanointerferometer that enables rapid and amplification-free detection of SARS-CoV-2 spike protein-coated pseudovirus directly from human saliva with the limit of detection (LOD) of about 400 copies per mL. This LOD is on par with that of qRT-PCR, making it 1000 to 100,000-fold more sensitive than commercial LFA tests. Using various combinations of negative selections during the screens for the aptamer targeting the receptor binding domain of the spike protein of SARS-CoV-2, we isolated two aptamers that can distinguish the Omicron and Delta variants. Integrating these two aptamers with LFA strips or the nanointerferometer sensors allows both detection and differentiation of the Omicron and Delta variants which has the potential to realize rapid triage of patients infected different SARS-CoV-2 variants.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , Pandemias , Oligonucleotídeos
18.
Rev Recent Clin Trials ; 18(3): 181-205, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37069722

RESUMO

The battle against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) associated coronavirus disease 2019 (COVID-19) is continued worldwide by administering firsttime emergency authorized novel mRNA-based and conventional vector-antigen-based anti- COVID-19 vaccines to prevent further transmission of the virus as well as to reduce the severe respiratory complications of the infection in infected individuals. However; the emergence of numerous SARS-CoV-2 variants is of concern, and the identification of certain breakthrough and reinfection cases in vaccinated individuals as well as new cases soaring in some low-to-middle income countries (LMICs) and even in some resource-replete nations have raised concerns that only vaccine jabs would not be sufficient to control and vanquishing the pandemic. Lack of screening for asymptomatic COVID-19-infected subjects and inefficient management of diagnosed COVID-19 infections also pose some concerns and the need to fill the gaps among policies and strategies to reduce the pandemic in hospitals, healthcare services, and the general community. For this purpose, the development and deployment of rapid screening and diagnostic procedures are prerequisites in premises with high infection rates as well as to screen mass unaffected COVID-19 populations. Novel methods of variant identification and genome surveillance studies would be an asset to minimize virus transmission and infection severity. The proposition of this pragmatic review explores current paradigms for the screening of SARS-CoV-2 variants, identification, and diagnosis of COVID-19 infection, and insights into the late-stage development of new methods to better understand virus super spread variants and genome surveillance studies to predict pandemic trajectories.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , COVID-19/epidemiologia , SARS-CoV-2 , Vacinas contra COVID-19 , Pandemias/prevenção & controle
19.
Talanta ; 258: 124422, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36907162

RESUMO

The outbreak of the novel coronavirus (SARS-CoV-2) has seriously harmed human health and economic development worldwide. Studies have shown that timely diagnosis and isolation are the most effective ways to prevent the spread of the epidemic. However, the current polymerase chain reaction (PCR) based molecular diagnostic platform has the problems of expensive equipment, high operation difficulty, and the need for stable power resources support, so it is difficult to popularize in low-resource areas. This study established a portable (<300 g), low-cost (<$10), and reusable molecular diagnostic device based on solar energy photothermal conversion strategy, which creatively introduces a sunflower-like light tracking system to improve light utilization, making the device suitable for both high and low-light areas. The experimental results show that the device can detect SARS-CoV-2 nucleic acid samples as low as 1 aM within 30 min.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Teste para COVID-19
20.
Sci Total Environ ; 878: 162953, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-36948304

RESUMO

On March 11, 2020, the World Health Organization declared the coronavirus disease 2019 (COVID-19), whose causative agent is the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), a pandemic. This virus is predominantly transmitted via respiratory droplets and shed via sputum, saliva, urine, and stool. Wastewater-based epidemiology (WBE) has been able to monitor the circulation of viral pathogens in the population. This tool demands both in-lab and computational work to be meaningful for, among other purposes, the prediction of outbreaks. In this context, we present a systematic review that organizes and discusses laboratory procedures for SARS-CoV-2 RNA quantification from a wastewater matrix, along with modeling techniques applied to the development of WBE for COVID-19 surveillance. The goal of this review is to present the current panorama of WBE operational aspects as well as to identify current challenges related to it. Our review was conducted in a reproducible manner by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews. We identified a lack of standardization in wastewater analytical procedures. Regardless, the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) approach was the most reported technique employed to detect and quantify viral RNA in wastewater samples. As a more convenient sample matrix, we suggest the solid portion of wastewater to be considered in future investigations due to its higher viral load compared to the liquid fraction. Regarding the epidemiological modeling, the data-driven approach was consistently used for the prediction of variables associated with outbreaks. Future efforts should also be directed toward the development of rapid, more economical, portable, and accurate detection devices.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , SARS-CoV-2 , Vigilância Epidemiológica Baseada em Águas Residuárias , Águas Residuárias , RNA Viral
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