Dipeptide-functionalized mesoporous silica spheres

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2004-02, Vol.234 (1), p.145-151
• Main Authors: Walcarius, Alain, Sayen, Stéphanie, Gérardin, Christine, Hamdoune, Faouzia, Rodehüser, Ludwig
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Carnosine; Chemical Sciences; Copper; Electrochemical detection; Ordered mesoporous silicas; Organic–inorganic hybrid composites
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2003.11.010

The preparation of surfactant-templated mesoporous silica spheres functionalized with carnosine moieties (dipeptide β-alanyl- l-histidine) is described. The procedure involves the hydrolysis and co-condensation of a carnosine-containing organotriethoxysilane and tetraethoxysilane (TEOS) in water/ethanol solution in the presence of ammonia acting as catalyst and cetyltrimethylammonium bromide (CTAB) as templating agent. The resulting organic–inorganic hybrid displays spherical shape as evidenced by electron microscopy and narrow particle size distribution. It exhibits high specific surface area (775 m 2 g −1), as determined from the N 2 adsorption isotherm, and the XRD pattern is characteristic of a mesostructure with wormholelike framework. Functionalization was confirmed by IR spectroscopy and solid-state 29 Si and 13 C MAS NMR. The regular mesoporous structure can be advantageously exploited in processes where diffusion is the rate-determining step, as exemplified for the electrochemical detection of trace copper(II) after preconcentration at a carbon paste electrode modified with the material.