Nanobiosensors Potentialities for Monitoring SARS-CoV-2 in the Environment

The worldwide pandemic of coronavirus disease-2019 (COVID-19) is a devastating and distressing scenario that highlights humanity's inability to build fast diagnostic tools for emerging infectious diseases. However, the majority of existing approaches have a significant probability of false negatives, leading in patient diag-nostic errors and prolonging therapy. Nanoparticles have shown significant improve-ment and have the potential to be used as a platform for quickly and accurately identifying viral infection. The relevance of nanoparticles is potential platforms for COVID-19 diagnostics was emphasized in this research. In addition, nanomaterials have surface chemistry, which may be beneficial for the bioconjugation of molecules, large surface potential, and a significant amplification impact on signals. Due to various potential benefits, metallic nanomaterials like gold, silver nanoparticles, and carbon-based nanomaterials (carbon nanotube and graphene), nanogels, and photonic crystals are utilized for biosensing applications. In compared to traditional techniques for identifying severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), this study covers the most relevant aspects of nanobiosensor-based diagnostics tech-niques. Additionally, major potential challenges and prospects associated with the advancement of these distinct sensors for SARS-CoV-2 detection are discussed in detail. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.

Emerging technologies for COVID-19, diagnosis, prevention, and management

Virus-related respiratory epidemics have been the most common cause of infectious disease worldwide for the past century. SARS-CoV-2 has been a threat to humanity all across the world from the beginning of 2020. The COVID-19 pandemic can only be controlled by identifying and isolating the new cases, thereby interrupting community transmission. Policymakers, health care providers, and interdisciplinary scientists must collaborate to ensure pandemic preparedness utilizing cutting-edge technology. Nonetheless, the development of novel nanotherapeutic and vaccination techniques is critical. To address these issues, further research about the SARS-CoV-2 structure as well as the precise immunological response it elicits in the human body is needed. © 2023 Elsevier Inc. All rights reserved.

Nanobiosensor-Based Microfluidic Point-of-Care Platforms: Fabrication, Characterization, and Applications

As the world fights the COVID-19 pandemic, point-of-care detection and diagnostic systems have gained immense importance. Microfluidics has revolutionized the domain of point-of-care (PoC) devices meant for the on-site detection of diseases. Microfluidic platforms provide an integrated, miniaturized, and cost-effective analytical alternative to conventional point-of-care devices with a massive potential for commercialization. These platforms also offer the additional advantage of low sample volume and lesser time for detection. The amalgamation of nanobiotechnology with microfluidics has given rise to highly selective and sensitive stand-alone devices that detect early disease onset and progression biomarkers. Early detection helps to decide the therapeutic strategy for the patient in as little time as possible. These devices are compact, portable, and convenient, hence ideal for PoC applications. The incorporation of nanoscale sensing elements, including nanoprobes, graphene, and magnetic and noble metal nanoparticles (Gold, Silver, and Platinum), further enhances the sensitivity of nanobiosensor-based immunoassays. The future of medical diagnostics heavily relies on these novel sensing platforms, thus helping in proper planning and management of the treatment of any disease. In this chapter, to better understand, we illustrate the fabrication, characterization, and applications of these intelligent point-of-care biosensing platforms. A brief account of challenges and future scope associated with applying such point-of-care nanobiosensors has also been discussed. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.

Emerging trends in point-of-care biosensing strategies for molecular architectures and antibodies of SARS-CoV-2.

COVID-19, a highly contagious viral infection caused by the occurrence of severe acute respiratory syndrome coronavirus (SARS-CoV-2), has turned out to be a viral pandemic then ravaged many countries worldwide. In the recent years, point-of-care (POC) biosensors combined with state-of-the-art bioreceptors, and transducing systems enabled the development of novel diagnostic tools for rapid and reliable detection of biomarkers associated with SARS-CoV-2. The present review thoroughly summarises and discusses various biosensing strategies developed for probing SARS-CoV-2 molecular architectures (viral genome, S Protein, M protein, E protein, N protein and non-structural proteins) and antibodies as a potential diagnostic tool for COVID-19. This review discusses the various structural components of SARS-CoV-2, their binding regions and the bioreceptors used for recognizing the structural components. The various types of clinical specimens investigated for rapid and POC detection of SARS-CoV-2 is also highlighted. The importance of nanotechnology and artificial intelligence (AI) approaches in improving the biosensor performance for real-time and reagent-free monitoring the biomarkers of SARS-CoV-2 is also summarized. This review also encompasses existing practical challenges and prospects for developing new POC biosensors for clinical monitoring of COVID-19.

CoVSense: Ultrasensitive Nucleocapsid Antigen Immunosensor for Rapid Clinical Detection of Wildtype and Variant SARS-CoV-2.

The widespread accessibility of commercial/clinically-viable electrochemical diagnostic systems for rapid quantification of viral proteins demands translational/preclinical investigations. Here, Covid-Sense (CoVSense) antigen testing platform; an all-in-one electrochemical nano-immunosensor for sample-to-result, self-validated, and accurate quantification of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N)-proteins in clinical examinations is developed. The platform's sensing strips benefit from a highly-sensitive, nanostructured surface, created through the incorporation of carboxyl-functionalized graphene nanosheets, and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) conductive polymers, enhancing the overall conductivity of the system. The nanoengineered surface chemistry allows for compatible direct assembly of bioreceptor molecules. CoVSense offers an inexpensive (<$2 kit) and fast/digital response (<10 min), measured using a customized hand-held reader (<$25), enabling data-driven outbreak management. The sensor shows 95% clinical sensitivity and 100% specificity (Ct<25), and overall sensitivity of 91% for combined symptomatic/asymptomatic cohort with wildtype SARS-CoV-2 or B.1.1.7 variant (N = 105, nasal/throat samples). The sensor correlates the N-protein levels to viral load, detecting high Ct values of ≈35, with no sample preparation steps, while outperforming the commercial rapid antigen tests. The current translational technology fills the gap in the workflow of rapid, point-of-care, and accurate diagnosis of COVID-19.

Recent advances in point of care testing for COVID-19 detection.

The World Health Organizations declaration of the COVID-19 pandemic was a milestone for the scientific community. The high transmission rate and the huge number of deaths, along with the lack of knowledge about the virus and the evolution of the disease, stimulated a relentless search for diagnostic tests, treatments, and vaccines. The main challenges were the differential diagnosis of COVID-19 and the development of specific, rapid, and sensitive tests that could reach all people. RT-PCR remains the gold standard for diagnosing COVID-19. However, new methods, such as other molecular techniques and immunoassays emerged. Also, the need for accessible tests with quick results boosted the development of point of care tests (POCT) that are fast, and automated, with high precision and accuracy. This assay reduces the dependence on laboratory conditions and mass testing of the population, dispersing the pressure regarding screening and detection. This review summarizes the advances in the diagnostic field since the pandemic started, emphasizing various laboratory techniques for detecting COVID-19. We reviewed the main existing diagnostic methods, as well as POCT under development, starting with RT-PCR detection, but also exploring other nucleic acid techniques, such as digital PCR, loop-mediated isothermal amplification-based assay (RT-LAMP), clustered regularly interspaced short palindromic repeats (CRISPR), and next-generation sequencing (NGS), and immunoassay tests, and nanoparticle-based biosensors, developed as portable instruments for the rapid standard diagnosis of COVID-19.

Recent Development in Plasmonic Nanobiosensors for Viral DNA/RNA Biomarkers.

Recently, due to the coronavirus pandemic, the need for early diagnosis of infectious diseases, including viruses, is emerging. Though early diagnosis is essential to prevent infection and progression to severe illness, there are few technologies that accurately measure low concentrations of biomarkers. Plasmonic nanomaterials are attracting materials that can effectively amplify various signals, including fluorescence, Raman, and other optical and electromagnetic output. In this review, we introduce recently developed plasmonic nanobiosensors for measuring viral DNA/RNA as potential biomarkers of viral diseases. In addition, we discuss the future perspective of plasmonic nanobiosensors for DNA/RNA detection. This review is expected to help the early diagnosis and pathological interpretation of viruses and other diseases.

Outlook of various diagnostics and nanodiagnostic techniques for COVID-19.

The sudden outbreak of the coronavirus disease 2019 (COVID-19) pandemic has brought to the fore the existing threat of disease-causing pathogens that affect public health all over the world. It has left the best healthcare systems struggling to contain the spread of disease and its consequences. Under challenging circumstances, several innovative technologies have emerged that facilitated quicker diagnosis and treatment. Nanodiagnostic devices are biosensing platforms developed using nanomaterials such as nanoparticles, nanotubes, nanowires, etc. These devices have the edge over conventional techniques such as reverse transcription-polymerase chain reaction (RT-PCR) because of their ease of use, quicker analysis, possible miniaturization, and scope for use in point-of-care (POC) treatment. This review discusses the techniques currently used for COVID-19 diagnosis, emphasizing nanotechnology-based diagnostic devices. The commercialized nanodiagnostic devices in various research and development stages are also reviewed. The advantages of nanodiagnostic devices over other techniques are discussed, along with their limitations. Additionally, the important implications of the utility of nanodiagnostic devices in COVID-19, their prospects for future development for use in clinical and POC settings, and personalized healthcare are also discussed.

Diagnostic accuracy of clinically applied nanoparticle-based biosensors at detecting SARS-CoV-2 RNA and surface proteins in pharyngeal swabs compared to RT-PCR as a reference test.

INTRODUCTION: Nanoparticle-based biosensors (NPBs) are point-of-care diagnostic platforms that can be used for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with high accuracy. AREAS COVERED: EBSCOhost Web, Embase, ProQuest, PubMed/MEDLINE, Scopus, Web of Science, and WHO Global Literature on Coronavirus Disease 2019 (COVID-19) were searched for relevant records published from 1 November 2019 to 30 April 2022. Records reporting original data on the accuracy of clinically applied nanoparticle-based biosensors at detecting SARS-CoV-2 RNA and surface proteins from pharyngeal swab specimens were considered. Findings were reported based on the PRISMA 2020 statement. The QUADAS-2 tool was used for assessment of quality and risk of bias among the included studies. EXPERT OPINION: A total of 50 relevant records were identified, of which 13 were included. The included studies explored the diagnostic performance of 13 clinically applied distinct nanoparticle-based biosensors in a total of 789 pharyngeal swabs collected from 376 COVID-19 patients and 413 otherwise healthy individuals. The mean sensitivity, specificity, and accuracy were 97.07%, 94.43%, and 96.91%, respectively, in comparison to RT-qPCR as the reference test. Considering their ease-of-operation, portability, low-cost manufacturing, NPBs could be considered suitable candidate diagnostic platforms for substituting RT-qPCR.

AuNP-based biosensors for the diagnosis of pathogenic human coronaviruses: COVID-19 pandemic developments.

The outbreak rate of human coronaviruses (CoVs) especially highly pathogenic CoVs is increasing alarmingly. Early detection of these viruses allows treatment interventions to be provided more quickly to people at higher risk, as well as helping to identify asymptomatic carriers and isolate them as quickly as possible, thus preventing the disease transmission chain. The current diagnostic methods such as RT-PCR are not ideal due to high cost, low accuracy, low speed, and probability of false results. Therefore, a reliable and accurate method for the detection of CoVs in biofluids can become a front-line tool in order to deal with the spread of these deadly viruses. Currently, the nanomaterial-based sensing devices for detection of human coronaviruses from laboratory diagnosis to point-of-care (PoC) diagnosis are progressing rapidly. Gold nanoparticles (AuNPs) have revolutionized the field of biosensors because of the outstanding optical and electrochemical properties. In this review paper, a detailed overview of AuNP-based biosensing strategies with the varied transducers (electrochemical, optical, etc.) and also different biomarkers (protein antigens and nucleic acids) was presented for the detection of human coronaviruses including SARS-CoV-2, SARS-CoV-1, and MERS-CoV and lowly pathogenic CoVs. The present review highlights the newest trends in the SARS-CoV-2 nanobiosensors from the beginning of the COVID-19 epidemic until 2022. We hope that the presented examples in this review paper convince readers that AuNPs are a suitable platform for the designing of biosensors.

Plasmonic nanobiosensors for detection of different targets

Plasmonic nanobiosensors have an enormous application range. It has the capacity to detect a wide variety of substances including metal, protein and even nucleic acids due to the superiority of SPR and LSPR. Plasmonic biosensors have been widely applied in the field of disease diagnosis, environmental conservation and food safety, eliminating barriers of traditional diagnosis methods and providing sensitive, quick and label-free devices. The applications of plasmonic biosensors in detection of many concerned diseases like cancer and SARS-CoV-2 are making an improvement on our medical condition. In the field of environmental protection, plasmonic-based biosensors also show great potential. They can efficiently detect two main types of contaminants, inorganic heavy metals involving Pb, Cd, As and Hg, and organic pollutants like polycyclic aromatic hydrocarbons (PAHs). Plasmonic biosensors could also overcome challenges on food allergen detection. This paper mainly focusses on SPR and LSPR-based nanobiosensors' application in environmental protection, food safety and health-care. © 2022 SPIE. Downloading of the is permitted for personal use only.

State-of-the-Art Smart and Intelligent Nanobiosensors for SARS-CoV-2 Diagnosis.

The novel coronavirus appeared to be a milder infection initially, but the unexpected outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), commonly called COVID-19, was transmitted all over the world in late 2019 and caused a pandemic. Human health has been disastrously affected by SARS-CoV-2, which is still evolving and causing more serious concerns, leading to the innumerable loss of lives. Thus, this review provides an outline of SARS-CoV-2, of the traditional tools to diagnose SARS-CoV-2, and of the role of emerging nanomaterials with unique properties for fabricating biosensor devices to diagnose SARS-CoV-2. Smart and intelligent nanomaterial-enabled biosensors (nanobiosensors) have already proven their utility for the diagnosis of several viral infections, as various detection strategies based on nanobiosensor devices are already present, and several other methods are also being investigated by researchers for the determination of SARS-CoV-2 disease; however, considerably more is undetermined and yet to be explored. Hence, this review highlights the utility of various nanobiosensor devices for SARS-CoV-2 determination. Further, it also emphasizes the future outlook of nanobiosensing technologies for SARS-CoV-2 diagnosis.

Zinc Nanomaterials: A Double-Edged Sword in Detection and Prevention against SARS-CoV-2 Spread (A Review)

The rise of ongoing Covid SARS-CoV-2 drove pandemic disease has created the perpetual interest for the assessment and improvement of reasonable progressed materials for controlling this and future unexpected viral diseases. One of the fundamental worries about this pandemic situation is the analysis and identification of infected patients. In this regard, the utilization of zinc-based nanomaterials to identify the vital biological markers of the SARS-CoV-2 remains a prevalent bother, whereas the advancement of particular and delicate devices is the essential objective. To obstruct virus proliferation, the expanding interest for self-disinfected covering requires elective materials to satisfy this problem. In this unique situation, zinc nanomaterials have given a fundamental commitment to the administration of Covid-19. Zinc nanomaterials have displayed huge antiviral action against a few infections like flu and Covids. This review delineates the importance of nanotechnology mediation in settling this tough condition.

Ultrasensitive Electrochemical Detection of Mutated Viral RNAs with Single-Nucleotide Resolution Using a Nanoporous Electrode Array (NPEA).

The detection of nucleic acids and their mutation derivatives is vital for biomedical science and applications. Although many nucleic acid biosensors have been developed, they often require pretreatment processes, such as target amplification and tagging probes to nucleic acids. Moreover, current biosensors typically cannot detect sequence-specific mutations in the targeted nucleic acids. To address the above problems, herein, we developed an electrochemical nanobiosensing system using a phenomenon comprising metal ion intercalation into the targeted mismatched double-stranded nucleic acids and a homogeneous Au nanoporous electrode array (Au NPEA) to obtain (i) sensitive detection of viral RNA without conventional tagging and amplifying processes, (ii) determination of viral mutation occurrence in a simple detection manner, and (iii) multiplexed detection of several RNA targets simultaneously. As a proof-of-concept demonstration, a SARS-CoV-2 viral RNA and its mutation derivative were used in this study. Our developed nanobiosensor exhibited highly sensitive detection of SARS-CoV-2 RNA (∼1 fM detection limit) without tagging and amplifying steps. In addition, a single point mutation of SARS-CoV-2 RNA was detected in a one-step analysis. Furthermore, multiplexed detection of several SARS-CoV-2 RNAs was successfully demonstrated using a single chip with four combinatorial NPEAs generated by a 3D printing technique. Collectively, our developed nanobiosensor provides a promising platform technology capable of detecting various nucleic acids and their mutation derivatives in highly sensitive, simple, and time-effective manners for point-of-care biosensing.

Neuroimaging a cytokine storm by transducing IL-1α to hippocampal cornu ammonis: COVID-19 SARS-CoV-2

Concerning the matter of depression, its full understanding pushes the envelope beyond clinical psychology and moves the subject further into the areas of Neuropsychopharmacology and Neuromolecular Imaging (NMI). Here, we studied, with the BRODERICK PROBE® acute and chronic stress-induced depression via the hypothalamic-pituitary-adrenal (HPA) axis. The “axis” is responsible for the emission of glucocorticoids during sympathetic nervous system activation. Negative feedback systems within areas of the hippocampus (HPC) and prefrontal cortex (PFC) prevent excessive amounts of glucocorticoids in the neurochemical environment and regulate the HPA axis production of these hormones. In depression, whether or not stress-induced, an increased concentration of glucocorticoids is present. In fact, when released by psychological or physical insult, glucocorticoids are accompanied by cytokines. The purpose of this work is to neuroimage a cytokine storm in the brain as it relates to COVID-19 SARS-CoV-2 patients. The advanced sensor nanobiotechnology, BRODERICK PROBE® transduced a small, protein cytokine, interleukin 1 alpha (IL-1α) to hippocampal Cornu Ammonis (CA-1) in two groups of animal subjects who are walking during neurotransmitter signaling. One genetically normal group was devoid of comorbidity to depression and indeed was also bred without viruses. The other genetic group was bred genetically depressed having platelet storage pool deficiency of the neurotransmitter, serotonin (5-HT);this group presented with Chediak-Higashi Syndrome and are Fawn-Hooded. Microdosing the pro-inflammatory IL-1α showed inherent neuroprotection of the hippocampal cytokine storm during real-time video tracking in Cornu Ammonis neurons in both nondepressed and depressed freely moving and walking subjects. The depressed subjects showed that the cytokine-induced storm began earlier than in nondepressed subjects while walking was increased in addition to enhanced stereotypy. Longer term studies in the same freely moving, walking subjects showed that the nondepressed were adapted to this cytokine brainstorm according to reliable sensor signaling signatures whereas the depressed subjects remained depressed. Thus, at the same time that we watched the brain immune derived cytokine storm directly coming to us online from HPC (CA-1) neurons, we monitored these motor skills with infrared photocell beams. Stereotypic grooming, nasopharyngeal systems were carefully assessed. These skills are important as they are related to respiratory SARS-CoV-2 insults and trauma. We watched online as the feared “hippocampal cytokine storm” was imaged in the depressed subject while immune T cell ratio CD4/CD8 was reversed. Tracking cytokine neuroinflammation transduced to HPC CA-1 neurons directly online while the subject is walking enables direct extrapolation to immune brain dysfunction in SARS-CoV-2 virus (Covid 19) patient data. © 2021 Elsevier Inc. All rights reserved.

Aptameric nanobiosensors for the diagnosis of COVID-19: An update.

COVID-19 pandemic has left a catastrophic effect on the world economy and human civilization. As an effective step towards controlling the transmission of viral infections during multiple waves of COVID-19, there is an urgent need to develop robust nanobiosensors for the detection of SARS-CoV-2 with high sensitivity, specificity, and fast analysis. Aptameric nanobiosensors are rapid and sensitive diagnostic platforms, capable of SARS-CoV-2 detection, which overcomes the limitations of the conventional techniques. This review article presents an outline of the aptameric nanobiosensors established for improved diagnosis of SARS-CoV-2 and the future perspectives are also covered.

Nanobiosensor-based diagnostic tools in viral infections: Special emphasis on Covid-19.

The rapid propagation of novel human coronavirus 2019 and its emergence as a pandemic raising morbidity calls for taking more appropriate measures for rapid improvement of present diagnostic techniques which are time-consuming, labour-intensive and non-portable. In this scenario, biosensors can be considered as a means to outmatch customary techniques and deliver point-of-care diagnostics for many diseases in a much better way owing to their speed, cost-effectiveness, accuracy, sensitivity and selectivity. Besides this, these biosensors have been aptly used to detect a wide spectrum of viruses thus facilitating timely delivery of correct therapy. The present review is an attempt to analyse such different kinds of biosensors that have been implemented for virus detection. Recently, the field of nanotechnology has given a great push to diagnostic techniques by the development of smart and miniaturised nanobiosensors which have enhanced the diagnostic procedure and taken it to a new level. The portability, hardiness and affordability of nanobiosensor make them an apt diagnostic agent for different kinds of viruses including SARS-CoV-2. The role of such novel nanobiosensors in the diagnosis of SARS-CoV-2 has also been addressed comprehensively in the present review. Along with this, the challenges and future position of developing such ultrasensitive nanobiosensors which should be taken into consideration before declaring these nano-weapons as the ideal futuristic gold standard of diagnosis has also been accounted for here.

Recent advances in nanomaterials based biosensors for point of care (PoC) diagnosis of Covid-19 - A minireview.

Early diagnosis and ultrahigh sample throughput screening are the need of the hour to control the geological spread of the COVID-19 pandemic. Traditional laboratory tests such as enzyme-linked immunosorbent assay (ELISA), reverse transcription polymerase chain reaction (RT-PCR) and computed tomography are implemented for the detection of COVID-19. However, they are limited by the laborious sample collection and processing procedures, longer wait time for test results and skilled technicians to operate sophisticated facilities. In this context, the point of care (PoC) diagnostic platform has proven to be the prospective approach in addressing the abovementioned challenges. This review emphasizes the mechanism of viral infection spread detailing the host-virus interaction, pathophysiology, and the recent advances in the development of affordable PoC diagnostic platforms for rapid and accurate diagnosis of COVID-19. First, the well-established optical and electrochemical biosensors are discussed. Subsequently, the recent advances in the development of PoC biosensors, including lateral flow immunoassays and other emerging techniques, are highlighted. Finally, a focus on integrating nanotechnology with wearables and smartphones to develop smart nanobiosensors is outlined, which could promote COVID-19 diagnosis accessible to both individuals and the mass population at patient care.

Rapid diagnostics of coronavirus disease 2019 in early stages using nanobiosensors: Challenges and opportunities.

The rapid outbreak of coronavirus disease 2019 (COVID-19) around the world is a tragic and shocking event that demonstrates the unpreparedness of humans to develop quick diagnostic platforms for novel infectious diseases. In fact, statistical reports of diagnostic tools show that their accuracy, specificity and sensitivity in the detection of COVID hampered by some challenges that can be eliminated by using nanoparticles (NPs). In this study, we aimed to present an overview on the most important ways to diagnose different kinds of viruses followed by the introduction of nanobiosensors. Afterward, some methods of COVID-19 detection such as imaging, laboratory and kit-based diagnostic tests are surveyed. Furthermore, nucleic acids/protein- and immunoglobulin (Ig)-based nanobiosensors for the COVID-19 detection infection are reviewed. Finally, current challenges and future perspective for the development of diagnostic or monitoring technologies in the control of COVID-19 are discussed to persuade the scientists in advancing their technologies beyond imagination. In conclusion, it can be deduced that as rapid COVID-19 detection infection can play a vital role in disease control and treatment, this review may be of great help for controlling the COVID-19 outbreak by providing some necessary information for the development of portable, accurate, selectable and simple nanobiosensors.

Biosensors for the Detection of Bacterial and Viral Clinical Pathogens.

Biosensors are measurement devices that can sense several biomolecules, and are widely used for the detection of relevant clinical pathogens such as bacteria and viruses, showing outstanding results. Because of the latent existing risk of facing another pandemic like the one we are living through due to COVID-19, researchers are constantly looking forward to developing new technologies for diagnosis and treatment of infections caused by different bacteria and viruses. Regarding that, nanotechnology has improved biosensors' design and performance through the development of materials and nanoparticles that enhance their affinity, selectivity, and efficacy in detecting these pathogens, such as employing nanoparticles, graphene quantum dots, and electrospun nanofibers. Therefore, this work aims to present a comprehensive review that exposes how biosensors work in terms of bacterial and viral detection, and the nanotechnological features that are contributing to achieving a faster yet still efficient COVID-19 diagnosis at the point-of-care.