The separation of highly pure single-chirality single-walled carbon nanotubes (SWCNTs) is challenging and also in demand due to their intrinsic physical, optical, and electronic properties. The use of single-chirality and their performance characteristics makes them a selective candidate for multifunctional applications and opens a new front in nanotube development. It has previously been reported that SWCNTs can be separated in various ways by employing direct control and post-synthesis approaches. Herein, we review the separation of single-chiralities of SWCNTs on account of simplicity and time/cost effectiveness by using gel chromatography. The most recent progress in the controlled synthesis of SWCNTs is comprehensively reviewed in terms of selective-diameter, single-chirality, and specific geometric shape. The method to achieve the single-chirality of SWCNTs is also highlighted. Besides addressing COVID-19 characteristics, epidemiology, and pathology, we also review the most recent developments in nano-biosensors for the rapid and early detection of COVID-19. Furthermore, the photothermal/bioimaging response of single-chirality is reviewed in order to enhance the cytotoxicity of drugs against cancer cells over simple carbon nanotubes (CNTs). The single-chirality allows for precise imaging (due to efficient absorption and emission) of tumors/blood vessels up to ∼10-fold higher by injecting a low dose. We hope this review stimulates further study on single-chirality controlled SWCNTs for practical applications.