Pore-confined synthesis of mesoporous nanocrystalline La-Ce phosphate films for sensing applications

A new method for the preparation of fluorescent mesoporous La-Ce phosphate films by spin coating is reported here. The structure is obtained by a pore-confined synthesis involving an in situ growth of La0.5Ce0.5PO4 nanoparticles inside the pores of a mesoporous silica thin film and the subsequent partial sintering. The removal of the sacrificial mesoporous silica matrix is achieved by chemical etching, which leaves on the substrate a La0.5Ce0.5PO4 mesoporous film exhibiting good adhesion properties and high fluorescence intensity that can be quenched by a water solution containing organo-phosphate bearing nitrophenyl groups. The sensing capabilities of these materials have been tested for the detection of pesticides in water.