Ship-in-a-bottle synthesis of fluorescence-labeled nanoparticles: applications in cellular imaging

Fluorescein (2-(6-hydroxy-3-oxo-(3H)-xanthen-9-yl)benzoic acid) has been prepared inside the pores of zeolite-Y via ship-in-a-bottle synthesis. Fluorescein, whose dimensions prevent it from entering through the approximately 7 A windows of the faujasite zeolite used, was prepared by the acid-catalyzed reaction of resorcinol and phthalic anhydride. In this article we report initial spectroscopic data as well as an example of the usefulness of these fluorescence-labeled nanoparticles for imaging applications such as confocal fluorescence microscopy. Encapsulated fluorescein shows a remarkable increase in photostability.