Zirconium umbelliferonephosphate - A luminescent organic-inorganic hybrid nanomaterial

Zirconium umbelliferonephosphate (ZrO(UFP)) is prepared by nucleation in the ionic liquid [MeBu3N] [NTf2]. According to electron microscopy the resulting nanoparticles exhibit mean particle diameters of about 50 nm. The organic-inorganic hybrid material ZrO(UFP) shows blue emission upon UV-excitation. Luminescence originates from the organic dye and is highly intense due to the molar amount of luminescent centers per nanoparticle. The as-prepared material turns out to be non-crystalline. Therefore, its chemical composition is validated by infrared spectroscopy, thermogravimetry, energy-dispersive X-ray analysis and elemental analysis. The results (i.e., thermal decomposition, Zr:P ratio, C-/H-concentration) are in accordance to the composition of ZrO(UFP). Upon addition of acid phosphatase the luminescence intensity of ZrO(UFP) is significantly increased due to enzymatic hydrolysis accompanied by a release of non-bound umbelliferone. Both aspects the increase in luminescence intensity as well as the release of umbelliferone - might be of future interest regarding biomedical application of ZrO(UFP) nanoparticles. (C) 2010 Elsevier Masson SAS. All rights reserved.