A new type of porous-silicon based photonic biosensor is presented. The device is a 1D planar photonic crystal
supporting resonant modes that can be excited at normal incidence. The study of theoretical performances demonstrates a
high sensitivity with similar performances in air and in aqueous environment. The experimental realization of the sensor
is discussed and preliminary biosensing experiments show very promising results.
Polyaromatic dyes were used to synthesize molecular nanocrystals in sol-gel thin films for sensor applications. Fluorescence Confocal Microscopy (FCM) and Transmission Electron Microscopy (TEM) experiments showed the advantages of our nanocrystallization process compared with microcrystallization in free solutions. Indeed, we obtained well-dispersed and spherical nanocrystals with a narrow size distribution, exhibiting a good crystallinity. Time-resolved fluorescence spectroscopy allowed us to measure fluorescence lifetimes of nanocrystals in presence of molecular probes. Then, chemical sensoring properties of these molecular nanocrystals were demonstrated.