Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, also known as 2019-nCov or nCovid-19) outbreak has become a huge public health issue due to its rapid transmission making it a global pandemic. Currently, there are no vaccines or drugs available for nCovid-19, hence early detection is crucial to help and manage the outbreak. Here, we report an inhouse built biosensor device (eCovSens) and compare it with a commercial potentiostat machine for the detection of nCovid-19 spike protein antigen (nCovid-19 Ag) in spiked saliva samples. A potentiostat based sensor was fabricated using fluorine doped tin oxide electrode (FTO) drop casted with gold nanoparticle (AuNPs) and immobilized with nCovid-19 monoclonal antibody (nCovid-19 Ab) to measure change in the electrical conductivity. Similarly, eCovSens was used to measure change in electrical conductivity by immobilizing nCovid-19 Ab on screen printed carbon electrode (SPCE). The performances of both sensors were recorded upon interaction of nCovid-19 Ab with its specific nCovid-19 Ag. Under optimum conditions, the FTO based immunosensor and proposed SPCE-based biosensor device displayed high sensitivity for early detection of nCovid-19 Ag, ranging from 1 fM to 1 µM. Our in-house developed eCovSens device can successfully detect nCovid-19 Ag at 10 fM concentration in standard buffer that is in close agreement with FTO/AuNPs sensor where AuNPs were used for the amplification of the electrical signal. The limit of detection (LOD) was found to be 90 fM with eCovSens and 120 fM with potentiostst in case of spiked saliva samples. The proposed portable point of care (PoC) eCovSens device can be used as an alternative diagnostic tool for the rapid (within 10-30 s) detection of nCovid-19 Ag traces directly in patient saliva samples that displayed high sensitivity, stability, and specificity.
Coronavirus disease 2019 (COVID-19), which started out as an outbreak of pneumonia, has now turned into a pandemic due to its rapid transmission. Besides developing a vaccine, rapid, accurate, and cost-effective diagnosis is essential for monitoring and combating the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its related variants on time with precision and accuracy. Currently, the gold standard for detection of SARS-CoV-2 is Reverse Transcription Polymerase Chain Reaction (RT-PCR), but it lacks accuracy, is time-consuming and cumbersome, and fails to detect multi-variant forms of the virus. Herein, we have summarized conventional diagnostic methods such as Chest-CT (Computed Tomography), RT-PCR, Loop Mediated Isothermal Amplification (LAMP), Reverse Transcription-LAMP (RT-LAMP), as well new modern diagnostics such as CRISPR–Cas-based assays, Surface Enhanced Raman Spectroscopy (SERS), Lateral Flow Assays (LFA), Graphene-Field Effect Transistor (GraFET), electrochemical sensors, immunosensors, antisense oligonucleotides (ASOs)-based assays, and microarrays for SARS-CoV-2 detection. This review will also provide an insight into an ongoing research and the possibility of developing more economical tools to tackle the COVID-19 pandemic.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, also known as 2019-nCov or COVID-19) outbreak has become a huge public health issue due to its rapid transmission making it a global pandemic. Here, we report fabricated fluorine doped tin oxide (FTO) electrodes/gold nanoparticles (AuNPs) complex coupled with in-house developed SARS-CoV-2 spike S1 antibody (SARS-CoV-2 Ab) to measure the response with Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV). The biophysical characterisation of FTO/AuNPs/SARS-CoV-2Ab was done via UV-Visible spectroscopy, Dynamic Light Scattering (DLS), and Fourier Transform Infrared Spectroscopy (FT-IR). The fabricated FTO/AuNPs/SARS-CoV-2Ab immunosensor was optimised for response time, antibody concentration, temperature, and pH. Under optimum conditions, the FTO/AuNPs/Ab based immunosensor displayed high sensitivity with limit of detection (LOD) up to 0.63 fM in in standard buffer and 120 fM in spiked saliva samples for detection of SARS-CoV-2 spike S1 antigen (Ag) with negligible cross reactivity Middle East Respiratory Syndrome (MERS) spike protein. The proposed FTO/AuNPs/SARS-CoV-2Ab based biosensor proved to be stable for up to 4 weeks and can be used as an alternative non-invasive diagnostic tool for the rapid, specific and sensitive detection of SARS-CoV-2 Spike Ag traces in clinical samples.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.