Recent trends in the development of nanomaterials for optical sensing of various human pathogens

As the global population increases tremendously, it drives the infectious disease rate upward. One vital cause of infectious disease is due to harmful pathogens that reside in water and food; a majority among them are transmittable from person to person. There is a huge responsibility in the hands of researchers and doctors to develop effective diagnostic techniques to detect and identify human pathogens (e.g., bacteria, fungi, virus). The conventional techniques developed are culture-based or count-based methods, polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay (ELISA). None of these techniques satisfy robust detection of pathogens. Therefore, there is a remarkable demand for developing a distinguished technique to detect human pathogens. The field of nanotechnology-based biosensors emerged in recent years that satisfies the requirements of pathogen detection, such as rapidity, specificity, selectivity, etc. Various sensing technologies were introduced. Among them, nanomaterial-based optical sensors comprising colorimetric, plasmonic, and forster resonance energy transfer (FRET)-based sensors played a major role in effective detection of pathogens using remarkable nanoparticles such as gold and silver nanoparticles (AuNPs, AgNPs) and fluorescent quantum dots (QDs). A detailed view of nanomaterials, optical techniques, and commercialized products are presented in this chapter.