Turn-on/turn-off fluorescent hybrid silica nanoparticles. A new promising material for selective anions’ sensing
Résumé
This work focused on the elaboration of a new fluorescent hybrid material based on spherical sil-
ica nanoparticle generated by sol–gel chemsitry (Stöber process). A fluorescent molecule (quaternized
pyridinoindolizin) was introduced on the inorganic framework via an organosilane entities possessing
hydrolysable group (methoxy group in the present case) to ensure the covalent linkage between the
inorganic host and the organic substrate. The material obtained was fully characterized with FTIR, 29 Si
and 13 C Solid state NMR, thermogravimetric and elemental analysis, Atomic force and scanning electron
microscopy and the fluorescence properties of these nano-objects were determined with a home-made
device. Finally, the influence of the counter-ion of the pyridinium fragment on the fluorescence emission
was also investigated. In this case, a specific behavior (turn-on, exaltation of emission) was observed
following exchange with perchlorate anions contrary to exchange with other anions such as acetate,
chloride and nitrate which provoke a quenching of fluorescence.