Virulent fungal plant pathogens are a serious threat to crop productivity and
are considered a major limitation to food security worldwide. To meet these challenges,
pathogen detection is crucial for taking appropriate measures to curb yield losses.
Disease diagnosis at an early stage is one of the best strategies for crop protection.
Earlier, traditional methods were used to diagnose and manage fungal diseases, which
included visual scouting of the disease symptoms and spray of fungicides. The utility
of immunoassays for early detection and precise identity has been appreciably stepped
forward following the improvement of enzyme-connected immunosorbent assay
(ELISA) and monoclonal antibodies. Nucleic acid-based diagnostic techniques have
turnout to be the preferred type because of their greater speed, specificity, sensitivity,
reliability, and reproducibility. The biosensor eliminates the need of sample preparation
and can be used for on-site detection of fungal pathogens at latent infection stages so
that preventive measures can be taken. Currently, multiple human and animal diseases
have been detected with the help of biosensors. However, reports on plant pathogen
detection using biosensors are still in infancy. Despite many applications of antibodies,
there are also multiple drawbacks, including high cost, low physical and chemical
stability, and the ethical issues associated with their use. Now, DNA based biosensors
are gaining popularity because of their sensitive and precise detection of DNA target
sequences. Immunological and DNA-based techniques combined with nanotechnology
offer highly sensitive and selective gel-free detection methods, and the lab-on-chip
(LOC) feature of biosensors makes them a very reliable tool in crop protection.