Doped mesoporous silica thin films for chemical vapor detection

Highly luminescent lanthanide-ligand complex (LLC) doped mesoporous silica thins films were fabricated for the use in trace chemical vapor detection. Different silicate precursors were made using the sol-gel process and spin-coated onto a substrate. Under UV excitation, the sensitizing ligands exhibited efficient energy transfer to the lanthanide to produce a detectable luminescence in the visible spectrum. Fluorescence quenching of the LCC by direct exposure of the films to fluorophosphate vapor was observed. Sensitivity to the chemical vapor was evaluated as a function of the sol-gel pore size, surface roughness, and thickness.