Fluorescent Monodisperse Silica Ellipsoids for Optical Rotational Diffusion Studies

@article{citeulike:1427736, abstract = {Abstract: We report on the preparation of monodisperse, fluorescent hematite-silica core-shell ellipsoids, with adjustable shapes ranging from spindles to nearly spheres, that are suitable for optical rotational diffusion studies. Hematite cores are grafted with poly(vinylpyrrolidone) which ensures colloidal stability during the silica coating provided by the base-catalyzed hydrolysis and polymerization of tetraethoxysilane. Using tetramethylammonium hydroxide as base instead of the volatile ammonia facilitates continuous seeded growth of silica to colloids with a desired aspect ratio. A convenient feature of the hematite-silica particles is the rapid dissolution of the iron oxide core by acid, producing hollow silica ellipsoids that can be optically matched to near transparency. The control of shape and size of the silica ellipsoids, their optical properties, and the fairly high yield in comparison to other preparation methods for nonspherical model colloids make the ellipsoids very suitable for quantitative studies. As a case in point, we have measured the rotational diffusion coefficient of fluorescent ellipsoids with rotational fluorescence recovery after photobleaching. Dye-labeled ellipsoids can be imaged with confocal microscopy.}, address = {Van't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands}, author = {Sacanna, S. and Rossi, L. and Kuipers, B. W. M. and Philipse, A. P. }, citeulike-article-id = {1427736}, doi = {10.1021/la052484o}, journal = {Langmuir}, keywords = {aspherical, diffusion, ellipsoidal, fluorescence, monodisperse, optical, rotational, silica}, month = {February}, number = {4}, pages = {1822--1827}, posted-at = {2007-08-27 00:28:02}, priority = {2}, title = {Fluorescent Monodisperse Silica Ellipsoids for Optical Rotational Diffusion Studies}, url = {http://dx.doi.org/10.1021/la052484o}, volume = {22}, year = {2006} }

TY - JOUR ID - citeulike:1427736 L3 - citeulike-article-id:1427736 TI - Fluorescent Monodisperse Silica Ellipsoids for Optical Rotational Diffusion Studies JF - Langmuir VL - 22 IS - 4 SP - 1822 EP - 1827 AD - Van't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands N2 - Abstract: We report on the preparation of monodisperse, fluorescent hematite-silica core-shell ellipsoids, with adjustable shapes ranging from spindles to nearly spheres, that are suitable for optical rotational diffusion studies. Hematite cores are grafted with poly(vinylpyrrolidone) which ensures colloidal stability during the silica coating provided by the base-catalyzed hydrolysis and polymerization of tetraethoxysilane. Using tetramethylammonium hydroxide as base instead of the volatile ammonia facilitates continuous seeded growth of silica to colloids with a desired aspect ratio. A convenient feature of the hematite-silica particles is the rapid dissolution of the iron oxide core by acid, producing hollow silica ellipsoids that can be optically matched to near transparency. The control of shape and size of the silica ellipsoids, their optical properties, and the fairly high yield in comparison to other preparation methods for nonspherical model colloids make the ellipsoids very suitable for quantitative studies. As a case in point, we have measured the rotational diffusion coefficient of fluorescent ellipsoids with rotational fluorescence recovery after photobleaching. Dye-labeled ellipsoids can be imaged with confocal microscopy. KW - aspherical KW - diffusion KW - ellipsoidal KW - fluorescence KW - monodisperse KW - optical KW - rotational KW - silica AU - Sacanna, S AU - Rossi, L AU - Kuipers, BWM AU - Philipse, AP PY - 2006/02/14/ UR - http://dx.doi.org/10.1021/la052484o ER -