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1.
Analytica Chimica Acta ; : 340860, 2023.
Article in English | ScienceDirect | ID: covidwho-2175682

ABSTRACT

In the context of globalization, individuals have an increased chance of being infected by multiple viruses simultaneously, thereby highlighting the importance of developing multiplexed devices. In addition to sufficient sensitivity and rapid response, multi-virus sensing techniques are expected to offer additional advantages including high throughput, one-time sampling for parallel analysis, and full automation with data visualization. In this paper, we review the optical, electrochemical, and mechanical platforms that enable multi-virus biosensing. The working mechanisms of each platform, including the detection principle, transducer configuration, bio-interface design, and detected signals, are reviewed. The advantages and limitations, as well as the challenges in implementing various detection strategies in real-life scenarios, were evaluated. Future perspectives on multiplexed biosensing techniques are critically discussed. Earlier access to multi-virus biosensors will efficiently serve for immediate pandemic control, such as in emerging SARS-CoV-2 and monkeypox cases.

2.
Small ; : e2205281, 2022.
Article in English | PubMed | ID: covidwho-2173456

ABSTRACT

The development of simple, cost-effective, rapid, and quantitative diagnostic tools remains critical to monitor infectious COVID-19 disease. Although numerous diagnostic platforms, including rapid antigen tests, are developed and used, they suffer from limited accuracy, especially when tested with asymptomatic patients. Here, a unique approach to fabricate a nanochannel-based electrochemical biosensor that can detect the entire virion instead of virus fragments, is demonstrated. The sensing platform has uniform nanoscale channels created by the convective assembly of polystyrene (PS) beads on gold electrodes. The PS beads are then functionalized with bioreceptors while the gold surface is endowed with anti-fouling properties. When added to the biosensor, SARS-CoV-2 virus particles block the nanochannels by specific binding to the bioreceptors. The nanochannel blockage hinders the diffusion of a redox probe;and thus, allows quantification of the viral load by measuring the changes in the oxidation current before and after virus incubation. The biosensor shows a low limit of detection of ≈1.0 viral particle mL(-1) with a wide detection range up to 10(8) particles mL(-1) in cell culture media. Moreover, the biosensor is able to differentiate saliva samples with SARS-CoV-2 from those without, demonstrating the potential of this technology for translation into a point-of-care biosensor product.

3.
Prakticky Lekar ; 102(4):171-176, 2022.
Article in Czech | Scopus | ID: covidwho-2168132

ABSTRACT

Aim: The review provides basic practical information about the use of biosensors in the rapid diagnosis of viral pathogens. Results: Thanks to evolutionary changes in the genome, viruses jump into the human population, where they cause serious epi-demics. Rapid POCT diagnostic tools based on biosensors will enable their use for clinical diagnosis needs outside of specialized laboratories. The combination of these devices with the techniques of 3D printing, microfluidic systems, nanotechnology and electrochemical detection significantly increases the usability of biosensors. Intensive research is carried out on a wide range of viruses, e.g. HIV, Ebola, influenza, hepatitis viruses. In connection with the global covid-19 pandemic, the development of nanobio-sensors is currently focused primarily on the detection of SARS-CoV-2. Conclusion: Available literature data suggest that fast sensors and biosensors have considerable clinical potential for the use in POCT. © 2022, Czech Medical Association J.E. Purkyne. All rights reserved.

4.
Nanophotonics ; 11(22):5041-5059, 2022.
Article in English | ProQuest Central | ID: covidwho-2162638

ABSTRACT

Highly infectious viral diseases are a serious threat to mankind as they can spread rapidly among the community, possibly even leading to the loss of many lives. Early diagnosis of a viral disease not only increases the chance of quick recovery, but also helps prevent the spread of infections. There is thus an urgent need for accurate, ultrasensitive, rapid, and affordable diagnostic techniques to test large volumes of the population to track and thereby control the spread of viral diseases, as evidenced during the COVID-19 and other viral pandemics. This review paper critically and comprehensively reviews various emerging nanophotonic biosensor mechanisms and biosensor technologies for virus detection, with a particular focus on detection of the SARS-CoV-2 (COVID-19) virus. The photonic biosensing mechanisms and technologies that we have focused on include: (a) plasmonic field enhancement via localized surface plasmon resonances, (b) surface enhanced Raman scattering, (c) nano-Fourier transform infrared (nano-FTIR) near-field spectroscopy, (d) fiber Bragg gratings, and (e) microresonators (whispering gallery modes), with a particular emphasis on the emerging impact of nanomaterials and two-dimensional materials in these photonic sensing technologies. This review also discusses several quantitative issues related to optical sensing with these biosensing and transduction techniques, notably quantitative factors that affect the limit of detection (LoD), sensitivity, specificity, and response times of the above optical biosensing diagnostic technologies for virus detection. We also review and analyze future prospects of cost-effective, lab-on-a-chip virus sensing solutions that promise ultrahigh sensitivities, rapid detection speeds, and mass manufacturability.

5.
Zhongguo Jiguang/Chinese Journal of Lasers ; 49(15), 2022.
Article in Chinese | Scopus | ID: covidwho-2143869

ABSTRACT

Significance In 2009, influenza A (H1N1) broke out in Mexico and the United States, influencing 214 countries and killing at least 14000 people. The novel coronavirus epidemic which broke out in 2020 has still been raging all over the world for two years as the results of the huge difficulty in the rapid and real-time epidemic prevention detection and the other reasons. In addition, the spread of other viruses including dengue virus (DENV) and human immunodeficiency virus (HIV) is also threatening human health significantly. Virus detection is the key to curb the spread of the viruses. At present, enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR), as the gold standard in the field of virus detection, can be used to detect and trace virus samples with a high sensitivity. But these samples need to be collected to the laboratory, and the viruses must be isolated and determined using the sophisticated lab equipment operated by professionals in order to get accurate results. Surface plasmon resonance (SPR)and local surface plasmon resonance (LSPR) biosensors may be an effective alternative, as their structures are simple and easy to be miniaturized. Especially, the LSPR-based device only needs a light source and some sensing elements. Once the sensing elements successfully capture the virus, the detection process will be quickly, sensitively, and selectively finished. These characteristics of the SPR and LSPR techniques show their great application potential in the field of virus detection, especially for the point-of-care testing with limited conditions. With the rapid development of SPR and LSPR-based virus detection researches, researchers have reviewed the progress of materials and structures of sensors, methods for plasmonic virus detection, and their characteristics of signal amplification, and so on. According to the four general virus detection methods and starting from the four kinds of target analytes captured by the sensor, this paper systematically outlines the latest researches of the SPR and LSPR techniques for detecting viruses, which are of great significance for their clinical application (Fig. 1). Progress First, according to the four methods for virus detection, the application progress of SPR and LSPR in the fields of antibody, antigen, nucleic acid, and virus particle detection is reviewed successively. For the SPR or LSPR sensors based on the binding principle of specific antigen-antibodies, the detection limit is further optimized by modifying the appropriate antigens or antibodies. More stable and inexpensive aptamers and molecularly imprinted polymers are expected to replace antibodies as sensor recognition elements to detect virus antigens or particles. Because the number of virus genomes in clinical samples is usually very small, the detection of nucleic acid by SPR or LSPR alone is limited. However, the detection of virus samples with the concentration at the femto scale can be realized by combining SPR or LSPR with DNA amplification and fluorescent substances. Second, the problems of biological medium contamination and repeatability encountered by biosensors as well as their solutions are introduced (Fig. 13). As for the contamination of biological media, self-assembled monolayers (SAM) can be synthesized on the surface of sensor elements to alleviate this problem. Riedel et al. further reduced or even completely inhibited the biological contamination of plasma and serum by synthesizing polymer brushes. In order to ensure the repeatability of sensing elements, Yoo et al. used magnetic beads replaced under the control of magnetic field as the sensing element, allowing that the sensor chip could still work stably after many repeated measurements. Third, the configurations and parameters of the SPR and LSPR sensors for virus detection in the past 15 years are listed (Table 1), and the advantages of the SPR and LSPR techniques are described. Finally, the optimization strategies of the SPR and LSPR techniques and the present existing problems are summarized. Moreover, e application prospect is also forecasted. Conclusion and Prospect According to the current research progress, the optimization strategy of the SPR sensor mainly focuses on film material sensitization and metal particle coupling sensitization. The former includes the application of 2D materials and molecular imprinting through the construction of surface films to enhance practicality and applicability. In contrast, the latter uses nanoparticles to form sandwich structures. The LSPR sensing strategies are concentrated on the design and optimization of nanoparticles or nanostructures, which are often combined with fluorescent substances such as quantum dots (QDs) to form sensing probes for virus detection by the light absorption peak shift or the fluorescence intensity change. The LSPR biosensors are normally easier to be miniaturized than the SPR counterparts. In a word, the SPR and LSPR sensors show great application prospects in the field of virus detection. Predictably, owing to the diversity of the SPR and LSPR virus sensor modifiers, it may be possible to detect specific viruses for multiple target analytes at the same time through the integration of sensor recognition elements, which enables the multi-dimensional evaluation of virus infection in a short time to avoid false negative and false positive cases. © 2022 Science Press. All rights reserved.

6.
Sens Actuators A Phys ; : 114052, 2022 Nov 24.
Article in English | MEDLINE | ID: covidwho-2122808

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been for its rapid worldwide spread. Each country had implemented city-wide lockdowns and immigration regulations to prevent the spread of the infection, resulting in severe economic consequences. Materials and technologies that monitor environmental conditions and wirelessly communicate such information to people are thus gaining considerable attention as a countermeasure. This study investigated the dynamic characteristics of batteryless magnetostrictive alloys for energy harvesting to detect human coronavirus 229E (HCoV-229E). Light and thin magnetostrictive Fe-Co/Ni clad plate with rectification, direct current (DC) voltage storage capacitor, and wireless information transmission circuits were developed for this purpose. The power consumption was reduced by improving the energy storage circuit, and the magnetostrictive clad plate under bending vibration stored a DC voltage of 1.9 V and wirelessly transmitted a signal to a personal computer once every 5 min and 10 s under bias magnetic fields of 0 and 10 mT, respectively. Then, on the clad plate surface, a novel CD13 biorecognition layer was immobilized using a self-assembled monolayer of -COOH groups, thus forming an amide bond with -NH2 groups for the detection of HCoV-229E. A bending vibration test demonstrated the resonance frequency changes because of HCoV-229E binding. The fluorescence signal demonstrated that HCoV-229E could be successfully detected. Thus, because HCoV-229E changed the dynamic characteristics of this plate, the CD13-modified magnetostrictive clad plate could detect HCoV-229E from the interval of wireless communication time. Therefore, a monitoring system that transmits/detects the presence of human coronavirus without batteries will be realized soon.

7.
American Journal of Transplantation ; 22(Supplement 3):706, 2022.
Article in English | EMBASE | ID: covidwho-2063463

ABSTRACT

Purpose: This study aimed to characterize the management and impact of respiratory viral infections on pediatric kidney transplantation waitlisted candidates. Method(s): An IRB-approved, anonymous REDCap survey was distributed to pediatric transplant nephrologist and infectious diseases practitioners from November 2021-January 2022 to members of the Pediatric Nephrology Research Consortium and the Pediatric Infectious Diseases Society via email. If multiple providers from the same center responded, questions related to center-wide practices were combined. Result(s): Sixty-six providers, 65 physicians and 1 nurse practitioner, responded to the survey from forty-eight different institutions (47 centers were in the United States). Providers estimated that respiratory viral infections were the most common cause of delays in transplant due to recipient infection. This fact has been highlighted during the pandemic with 46% of centers reporting they had delayed transplants for institutional reasons related to the pandemic and 38% had delayed transplants for active SARS-CoV-2 infection in a recipient, even before the omicron surge. Despite the impact of respiratory viral detection in waitlisted patients, over 80% of centers did not have a policy regarding delays for respiratory viral infections including SARS-CoV-2. Pre-transplant recipient screening for non-SARS-CoV-2 viral infections was not routine in 77% of centers but 45% of providers indicated they would delay a living donor transplant if they knew the recipient had an asymptomatic respiratory viral infection. For recipients with symptomatic respiratory viral infection, 95% and 87% of providers would delay transplant (living donor and deceased donor transplants respectively). Fifty-nine percent of providers indicated they would proceed with transplant after a waiting period ranging from one week to two months. Conclusion(s): Providers recognize that respiratory viral infections, not limited to SARS-CoV-2, are a common cause of pediatric kidney transplant delay. Most centers do not have defined approaches to screening and management of non-SARS CoV-2. Prospective studies and policies for screening and management of respiratory viral infections in waitlisted pediatric kidney transplant should be considered.

8.
Investigative Ophthalmology and Visual Science ; 63(7):2373-A0057, 2022.
Article in English | EMBASE | ID: covidwho-2057947

ABSTRACT

Purpose : With this research project we wanted to approach the question of whether SARS-CoV 2 can infect the eye. In order to infect ocular tissues, virus-specific receptors;coreceptors or proteases must be present in the eye tissue. SARS-CoV 2 uses the human angiotensin converting enzyme 2 (ACE2) receptor to enter cells. In addition, the mammalian serine protease TMPRSS2, the protease furin and the glycoprotein neuropilin are identified as relevant proteases for the interaction of the virus with ACE2. Last year, we were able to show that ACE2 is significantly more expressed in ocular tissue of covid patients. Here the expression level of the co-receptor and glia markers, as well as the present of virus was confirmed in this study. Methods : Seven eyes from donors without covid disease (COVID-) as well as ten fixed eyes from COVID-19 patients (COVID+) were analysed for their expression profile of ACE2, TMPRSS2, neuropilin and furin in the retina and cornea. The ocular tissues were examined for protein expression by immunohistochemical staining or for RNA expression by quantitative real-time PCR. In addition, viral spike protein was detected histologically in eyes, and expression profiles of GFAP and Iba-1 were assessed. Results : Similar to ACE2 and TMPRSS2, the two proteases neuropilin and furin were detected in the retina and cornea. Interestingly, the expression profile differed in terms of strength and localization, especially in the retina. The presence of the virus in both cornea and retina was also demonstrated by the detection of viral spike protein. In all COVID+ retinas, strong GFAP staining was observed as well as some Iba-1 positive cells, suggesting activation of macro- and microglia. Conclusions : Expression of ACE2, TMPRSS2, furin and neuropilin was demonstrated in COVID+ ocular tissues. In addition to the virus detection in retina and cornea, a glial reaction could also be observed. One can therefore assume an infection of the eye in these cases. However, in summary it can be said that an infection of the eye tissue is possible since all demanded receptors are present.

9.
Mol Biotechnol ; 2022 Oct 01.
Article in English | MEDLINE | ID: covidwho-2048560

ABSTRACT

An ongoing pandemic of coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). So far, there have been various approaches for SARS-CoV-2 detection, each having its pros and cons. The current gold-standard method for SARS-CoV-2 detection, which offers acceptable specificity and sensitivity, is the quantitative reverse transcription-PCR (qRT-PCR). However, this method requires considerable cost and time to transport samples to specialized laboratories and extract, amplify, and detect the viral genome. On the other hand, antigen and antibody testing approaches that bring rapidity and affordability into play have lower sensitivity and specificity during the early stages of COVID-19. Moreover, the immune response is variable depending on the individual. Methods based on clustered regularly interspaced short palindromic repeats (CRISPR) can be used as an alternative approach to controlling the spread of disease by a high-sensitive, specific, and low-cost molecular diagnostic system. CRISPR-based detection systems (CRISPR-Dx) target the desired sequences by specific CRISPR-RNA (crRNA)-pairing on a pre-amplified sample and a subsequent collateral cleavage. In the present article, we have reviewed different CRISPR-Dx methods and presented their benefits and drawbacks for point-of-care testing (POCT) of suspected SARS-CoV-2 infections at home or in small clinics.

10.
Future Virology ; 17(7):429-439, 2022.
Article in English | EMBASE | ID: covidwho-2032730

ABSTRACT

Aim: This study aimed to evaluate chemokine receptor 5 delta 32 (CCR5-δ32) mutation and HIV-1 surveillance drug-resistance mutations (SDRMs) in peripheral blood mononuclear cells of long-term non progressors (LTNPs) of HIV-1-infected individuals. Materials & methods: This research was performed on 197 treatment-naive HIV-1-infected patients. After follow-up, it was determined that 15 (7.6%) of these people were LTNPs. The PCR assay was performed to identify the CCR5 genotype and HIV-1 SDRMs. Results: One (6.7%) of the LTNPs was heterozygous (wt/δ32) for the CCR5 delta 32 (CCR5δ32). However, none of the individuals was homozygous for this mutation (δ32/δ32). Moreover, none of the LTNPs showed HIV-1 SDRMs. The CRF35-AD subtype was the most dominant subtype, with a percentage of 93.3%. Conclusion: Iranian elite controllers are negative for CCR5-delta 32 homozygous genotype and drug resistance against antiretroviral drugs.

11.
Biosensors and Bioelectronics: X ; 12:100230, 2022.
Article in English | ScienceDirect | ID: covidwho-2031165

ABSTRACT

Co-circulation of respiratory viruses compounded by similarities in clinical presentation and mode of transmission underscores the need for broad range pathogen detection. Accurate identification and diagnosis at the point-of-need is critical to limiting disease spread. A novel point-of-need Raman spectroscopy-based platform is described for rapid detection of multiple respiratory pathogens in nasal swab samples with high sensitivity and specificity. The system takes advantage of a counter-propagating Gaussian beam focused within the sample chamber that augments the Raman signal of pathogens. Combined with multiclass machine learning spectral analysis via Gradient Boosting Machine, accurate identification of SARS-CoV-2, human coronaviruses OC43, NL63, 229E, Influenza A (H1N1), respiratory syncytial virus, and Streptococcus pyogenes in spiked clinical nasal swab samples was demonstrated at 99% sensitivity and 93% specificity. The limit of detection was assessed using binary class Support Vector Machine with SARS-CoV-2 in nasal swab samples against negative control at 2.2 × 104 virions/swab. The spectrometer can be operated by minimally trained personnel with software-generated diagnostic yes/no results in 2 min or less, making it well suited for point-of-need applications. Furthermore, adaptive algorithms can detect and differentiate new and emerging variants using a Raman spectral database.

12.
Biosens Bioelectron ; 217: 114721, 2022 Dec 01.
Article in English | MEDLINE | ID: covidwho-2031162

ABSTRACT

Rapid and sensitive pathogen detection is important for prevention and control of disease. Here, we report a label-free diagnostic platform that combines surface-enhanced Raman scattering (SERS) and machine learning for the rapid and accurate detection of thirteen respiratory virus species including SARS-CoV-2, common human coronaviruses, influenza viruses, and others. Virus detection and measurement have been performed using highly sensitive SiO2 coated silver nanorod array substrates, allowing for detection and identification of their characteristic SERS peaks. Using appropriate spectral processing procedures and machine learning algorithms (MLAs) including support vector machine (SVM), k-nearest neighbor, and random forest, the virus species as well as strains and variants have been differentiated and classified and a differentiation accuracy of >99% has been obtained. Utilizing SVM-based regression, quantitative calibration curves have been constructed to accurately estimate the unknown virus concentrations in buffer and saliva. This study shows that using a combination of SERS, MLA, and regression, it is possible to classify and quantify the virus in saliva, which could aid medical diagnosis and therapeutic intervention.


Subject(s)
Biosensing Techniques , COVID-19 , COVID-19/diagnosis , Humans , Machine Learning , SARS-CoV-2 , Silicon Dioxide , Silver/chemistry , Spectrum Analysis, Raman/methods
13.
2022 IEEE International Conference on Communications, ICC 2022 ; 2022-May:1444-1449, 2022.
Article in English | Scopus | ID: covidwho-2029230

ABSTRACT

Since the outbreak of the COVID-19 pandemic, indoor air quality has become increasingly important. The interdisciplinary grouping of academic majors focused on the pursuit of solutions that identify or prevent the airborne transmission and inhalation, initially of Coronavirus and secondarily of viruses such as influenza. Throughout the research work, we aim to contribute by elaborating the teaching-learning technique to select and identify the optimal attributes of viruses' variants of the indoor atmosphere. The novelty is based on the objective to enable real-time identification of the density of the airborne molecules to prevent virus propagation. Several sensors and systems came into the spotlight by conducting a systematic literature review that, in conjunction with our innovative idea, could construct a revolutionary new solution that could eliminate the risk of exposure to viable viruses. The proposed teaching-learning based attribute selection optimisation is among the most popular bio-inspired meta-heuristic methods. Therefore, evolutionary logic and provocative performance can be widely utilised to solve the aforementioned humanitarian problem. The proposed frame constitutes three pivotal steps: the new update mechanism, the novel method of selecting the principal teacher in the teacher's phase, and the support vector machine method to compute the fitness function of optimisation. © 2022 IEEE.

14.
6th International Conference on Biomedical Engineering and Applications, ICBEA 2022 ; : 130-136, 2022.
Article in English | Scopus | ID: covidwho-2020428

ABSTRACT

At the end of 2019, Coronavirus disease (COVID-19) started and as of now, it is still the number one problem of the world today. This virus can be transmitted through droplets of saliva from an infected person which can be from a sneeze, cough, and exhales. As of now, there are a total of 111 million cases of the virus and there are technologies that were introduced to help in the detection of the infection and to reduce the spread of the virus. One of this technology is the Reverse Transcription-Polymerase Chain Reaction (RT-PCR) Machine. This machine detects any specific genetic material, including a virus. Samples from the body are treated with several chemical solutions which remove substances and only allow Ribonucleic Acid (RNA) to remain. But the problem with this machine is the elicitation of false-positive and false-negative results and certain malfunctions. Due to the issues in using RT-PCR, our team has come up with a newer and improvised version of the machine and called it COVIDBIT. COVIDBIT is a more simplified and portable version of the RT-PCR at a cheaper price. In this study, the team analyzed COVIDBIT as a virus detection device and an alternative for RT-PCR machine using SEM model and found out that there is a significant difference in terms of effectiveness and portability in usage and showed that the 210 respondents from the medical industry are most likely to use these kinds of machine. © 2022 ACM.

15.
6th International Conference on Biomedical Engineering and Applications, ICBEA 2022 ; : 116-119, 2022.
Article in English | Scopus | ID: covidwho-2020427

ABSTRACT

A global pandemic of SARS-CoV-2 was caused around the world. The virus is highly contagious and rapidly spreads. Early detection of the virus is crucial to prevent its spread and control outbreaks. Owing to the drawbacks of waiting time and high cost involved in polymerase chain reaction (PCR) testing, low-cost and accurate detection setups with the possibility of being realized as portable systems are desirable. In this study, we examined the feasibility of using a small spectrometer in conjunction with optical biosensors as a measurement system. According to the experimental results related to different concentrations of SARS-CoV-2 ranging from 106 to 102 copies/mL, the surface-mounted device (SMD) size spectrometer and benchtop fiber-optic spectrometer showed good agreement, demonstrating the possibility of using tiny spectrometers to detect the virus at different concentrations using optical biosensors. © 2022 ACM.

16.
Clinical and Translational Biophotonics, Translational 2022 ; 2022.
Article in English | Scopus | ID: covidwho-2012125

ABSTRACT

Localized surface plasmon resonance of Au nanodots array are very sensitive and resonance field disturbance due to 100 nm sized SARS-CoV-2 virus can be detected via resonance wavelength shift. We have proposed Au nanodots (100 nm diameter and 200 nm pitch) array plasmonic biosensing platform for SARS-CoV-2 virus detection. © 2022 The Author(s).

17.
Front Microbiol ; 13: 939666, 2022.
Article in English | MEDLINE | ID: covidwho-2009883

ABSTRACT

Plant viruses threaten crop yield and quality; thus, efficient and accurate pathogen diagnostics are critical for crop disease management and control. Recent advances in sequencing technology have revolutionized plant virus research. Metagenomics sequencing technology, represented by next-generation sequencing (NGS), has greatly enhanced the development of virus diagnostics research because of its high sensitivity, high throughput and non-sequence dependence. However, NGS-based virus identification protocols are limited by their high cost, labor intensiveness, and bulky equipment. In recent years, Oxford Nanopore Technologies and advances in third-generation sequencing technology have enabled direct, real-time sequencing of long DNA or RNA reads. Oxford Nanopore Technologies exhibit versatility in plant virus detection through their portable sequencers and flexible data analyses, thus are wildly used in plant virus surveillance, identification of new viruses, viral genome assembly, and evolution research. In this review, we discuss the applications of nanopore sequencing in plant virus diagnostics, as well as their limitations.

18.
Heliyon ; 8(9): e10472, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-2004109

ABSTRACT

Due to the recent COVID-19 pandemic that occurred worldwide since 2020, scientists and researchers have been studying methods to detect the presence of the virus causing COVID-19 disease, namely SARS-CoV-2. Optical spectroscopy is a method that employs the interaction of light in detecting virus on samples. It is a promising method that might help in detecting the presence of SARS-CoV-2 in samples. Four optical spectroscopy methods are discussed in this paper: ultraviolet (UV), infrared (IR), Raman spectroscopy and fluorescence spectroscopy. UV and IR spectroscopy differ in wavelength range (less than 400 nm for UV, more than 700 nm for IR). Raman spectroscopy involves shift in wavelength due to scattering of light. Fluorescence spectroscopy involves difference in wavelength between absorbed and emitted light due to vibrational relaxation. These four methods had been proven to differentiate healthy samples from virus-infected samples. UV spectroscopy is useful in determining presence of virus based on 260 nm/280 nm absorbance ratio. However, its usefulness is limited due to its destructive properties on virus at sufficiently high intensity. Meanwhile, IR spectroscopy has becoming popular in studies involving virus samples. Mid-infrared (MIR) spectroscopy is most commonly used among IR spectroscopy as it usually provides useful information directly from spectral data. Near infrared (NIR) spectroscopy is also used in studying virus samples, but additional methods such as principal component analysis (PCA) and partial least squares (PLS) are required to process raw spectral data and to identify molecules based on spectral peaks. On the other hand, Raman spectroscopy is useful because spectral data can be analyzed directly in identifying vibrational modes of specific molecules in virus samples. Fluorescence spectroscopy relies on interaction between viral particles and fluorescent tags for the detection of virus based on improvement or quenching of fluorescent signal. Due to non-invasive properties of virus samples, IR, Raman and fluorescence spectroscopy will be used more often in future studies involving virus detection in infected samples.

19.
NeuroQuantology ; 20(8):5664-5673, 2022.
Article in English | EMBASE | ID: covidwho-1998069

ABSTRACT

SARS-CoV2 is a new virus that began rapidly spreading in Wuhan Province, China, on December 2019 and has since spread around all the world. The infections methods can be considered as transportation techniques were one of the key factors that contributed to the global pandemic that occurred on March, 2020. The virus has the ability to infect various organs of the human body, including lungs, heart, kidneys, and others, causing severe damage and maybe death. As the virus spreads quickly, numerous ways for detecting the infection have emerged to assist doctors in treating the patient. This paper concentrate about using X-ray images that are collected from Kaggle data set to detect the infections of corona virus. These data are pre-trained (fine-tuned) to specific networks like Visual Geometry Group (vgg19) and MobileNet to get benefit of the CNN properties (image processing, segmentation and classification). The motivation of this paper include section (1) introduction with related work, section (2) (CNN)algorithm with details, section (3) contain the the data set properties while section (4) included the results and discussions. The proposed technique (vgg19 network) performed the best result (99%) validation accuracy.

20.
Biosensors (Basel) ; 12(8)2022 Aug 22.
Article in English | MEDLINE | ID: covidwho-1997516

ABSTRACT

With the rise of zoonotic diseases in recent years, there is an urgent need for improved and more accessible screening and diagnostic methods to mitigate future outbreaks. The recent COVID-19 pandemic revealed an over-reliance on RT-PCR, a slow, costly and lab-based method for diagnostics. To better manage the pandemic, a high-throughput, rapid point-of-care device is needed for early detection and isolation of patients. Electrochemical biosensors offer a promising solution, as they can be used to perform on-site tests without the need for centralized labs, producing high-throughput and accurate measurements compared to rapid test kits. In this work, we detail important considerations for the use of electrochemical biosensors for the detection of respiratory viruses. Methods of enhancing signal outputs via amplification of the analyte, biorecognition of elements and modification of the transducer are also explained. The use of portable potentiostats and microfluidics chambers that create a miniature lab are also discussed in detail as an alternative to centralized laboratory settings. The state-of-the-art usage of portable potentiostats for detection of viruses is also elaborated and categorized according to detection technique: amperometry, voltammetry and electrochemical impedance spectroscopy. In terms of integration with microfluidics, RT-LAMP is identified as the preferred method for DNA amplification virus detection. RT-LAMP methods have shorter turnaround times compared to RT-PCR and do not require thermal cycling. Current applications of RT-LAMP for virus detection are also elaborated upon.


Subject(s)
Biosensing Techniques , COVID-19 , Viruses , Biosensing Techniques/methods , COVID-19/diagnosis , Humans , Nucleic Acid Amplification Techniques , Pandemics , Point-of-Care Systems , Viruses/genetics
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