Superparamagnetic cluster-nano particles-porous composite bead and fabrication method thereof

A superparamagnetic cluster-nanoparticles-porous composite bead comprising:

• a cluster of superparamagnetic nanoparticles;
• a central porous bead veiling the cluster;
• nanoparticles radially coupled to an outer surface of the central porous bead by virtue of an electrostatic attraction;
• and
• a porous layer formed to veil the nanoparticles,
• wherein the nanoparticle is at least one type selected from a group consisting of light-emitting nanoparticle, magnetic nanoparticle, metallic nanoparticle and metal oxide nanoparticle.

A method for fabricating a superparamagnetic cluster-nanoparticles-porous composite bead comprising:

• (a) mixing a first solution containing a superparamagnetic cluster with materials needed for fabrication of a porous body so as to prepare a solution containing the cluster and a central porous bead grown to veil a surface of the cluster;
• (b) preparing a second solution by bonding molecules having a first charge onto the outer surface of the central porous bead;
• (c) preparing a third solution, which contains nanoparticles and has a second charge reverse to the first charge;
• (d) mixing the second solution obtained at step (b) with the third solution such that nanoparticles are coupled onto the outer surface of the central porous bead by virtue of an electrostatic attraction;
• and
• (e) mixing the solution obtained at step (d) with materials needed for fabrication of the porous body to form a porous layer to veil the nanoparticles,
• wherein the nanoparticle at step (c) is at least one selected from a group consisting of light-emitting nanoparticle, magnetic nanoparticle, metallic nanoparticle and metal oxide nanoparticle.