The invention relates to a hybrid silica bead having a millimeter scaled-size adapted for the entrapment of a component or a bioactive substance, wherein the bead is formed of a porous core comprised of a hybrid alginate-silica (1) and an external porous layer comprising silica and a silica concentrator (2). The present invention is also related to a one-pot process for the preparation of these hybrid beads and to the use of the beads according to the invention.