Recent Advancements in Graphene Biosensors for the detection of Pathogens - A Review

Due to increasing rate of growth of pathogens throughout the world, there have been many epidemics in the recent past like Zika virus, Ebola virus and dengue fever. In many cases, the physicians were not able to treat the infected patients early enough to save their lives. One of the major reasons for this was because the physicians were only approached by the patients when some major symptoms developed. Or even if they approached the physician, the pathogen was detected very late due to the techniques used, that were slow, expensive, not very accurate and not simple. The techniques didn't have a low detection limit as well, therefore it was almost impossible to detect the pathogen at a very early stage. To resolve these problems, extensive research is being carried out on graphene based biosensors. Graphene is a one atom thick single layer of sp2 hybridized carbons molecules. The extraordinary physical properties that it has, makes it an ideal material for the fabrication of biosensors. When the biosensors fabricated from graphene were tested, they delivered superior results and detected pathogens at a very low detection limits. In this review, we discuss the recent advancements within the field of graphene based sensors used primarily for the detection of pathogens. Further, the fabrication of the sensors for the detection of each pathogen has been discussed. The first section introduces graphene, its physiochemical properties. The second part focuses on the basic idea with which the graphene biosensor is designed. The third section discusses the detailed concept behind the detection of each pathogen covered in this review. Various methods for graphene modification have been discussed including functionalization using polymers and use of dopants with metal/metal oxide nanoparticles. And finally, the review concludes with the future applications and usefulness of graphene biosensors.