Silica particles doped with quercetin-Al3+ complex were prepared by hydrolysis and condensation of tetraethylorthosilicate (TEOS) using acid and basic catalysis. The acid catalysis resulted in particles with diameter about 200 nm. Basic catalysis with TEOS was performed over a quercetin doped alumina-sol used as a core precursor, and fluorescent finger-shaped SiO2 particles were obtained. The quercetin-alumina-SiO2 fluorescence decays are biexponential, and this character is ascribed to two types of quercetin-Al3+ complexes entrapped in the core of the system.
silica particles; fluorescence spectroscopy; probes; flavonoid
