Indicator immobilization on Fabry-Perot nanocavities towards development of fiber optic sensors

Two fabrications processes based on the Electrostatic Self Assembly method have been studied in order to develop a potential fibre optic sensor for detection volatile organic compounds (VOCs). A nano Fabry-Perot is constructed onto a cleaved ended fibre optic pigtail, and is doped with a vapochromic complex of formula [Au2Ag2(C6F5)4(C6H5N)2]. This material is presented in form of red powders, shows fluorescence at 585 nm when illuminated with a light at 380 nm, and suffers changes in its color and refractive index when is exposed to VOCs. Both different possibilities of doping the nano Fabry-Perot studied keep the optical properties of the sensing material. To verify the sensing ability of the final devices, they have been exposed to ethanol vapors, taking measures of their absorbance spectra and the intensity modulated reflected signal at 850 nm, employing a reflection scheme.