Developments and challenges in coronavirus diagnoses: A biosensor point of view

The COVID-19 pandemic is a global health issue. The causative agent is a virus, viz. SARS-CoV-2, belonging to Orthocoronavirinae (a subfamily of Coronaviridae), which comprises a group of RNA viruses responsible for various respiratory diseases ranging from mild threats to severe infection cascades. Early and accurate diagnosis along with effective treatment strategies for the viral infection are the key to management of the ongoing pandemic. Existing methods such as molecular (RT-PCR, (q)RT-PCR), serological enzyme-linked immunosorbent assay, and immunoassay (based on detecting SARS-CoV-2 antigens and antibodies) are used to quickly diagnose viral infections, and in parallel, certain drugs are also used in treatment. Prescribed diagnostic and treatment approaches are associated with several related advantages and disadvantages. One example is rapid kits. They are used in viral diagnosis, but they have poor percentage accuracy in result prediction for certain antiviral agents. To overcome this issue, advanced technologies like optical sensors, nanosensors, microfluidics, etc., have been developed and are used as novel point-of-care theragnostic solutions to manage SARS-CoV-2 treatment. To achieve maximum protection from a viral infection, it is important to present all theragnostic progress concisely so it can be quickly overviewed by clinicians, scientists, and civil society. In the background of the current need for COVID-19 management, an attempt has been made to provide a comprehensive review of existing rapid diagnostics and therapeutic approaches.