Photonics is an enabling technology, present in our daily lives. Biophotonics and Nanophotonics are well established multidisciplinary fields of research which exploit photonics for biomedical sciences and applications, in the former, and photonics in the nanoworld, in the later. When combined, the so-called nanobiophotonics, encompasses all these research areas. In this talk, I will describe how biophotonics technique can be used for optical imaging, particularly exploiting optical coherence tomography (OCT) applied to dentistry and dermatology. Also, I will show how dielectric or metal nanoparticles can be used to enhance optical imaging in OCT, or as nanothermometers. Finally, I shall give an example of how silver nanoparticles can be used to mitigate the spread of Aedes aegypti by killing the larvae in early stages, before they develop into mosquitos.