Magnetically tunable plasmon coupling of nanoshells enabled by space-free confined growth

1 . A method of forming magnetic/plasmonic hybrid structures comprising:

synthesizing colloidal magnetic nanoparticles;

modifying the magnetic nanoparticles in a solution of a polymeric ligand;

binding metal seed nanoparticles to the surface of the magnetic nanoparticles;

performing a seed-mediated growth on the metal seed nanoparticles by reducing a metal salt in solution to form the magnetic/plasmonic hybrid structures; and

coating the magnetic nanoparticles containing surface-attached metal seed nanoparticles with a polymer shell of resorcinol-formaldehyde resin prior to performing the seed-mediated growth.

2 . The method according to claim 1 , further comprising:

removing the resorcinol-formaldehyde coating from the plasmonic structures after the seed-mediated growth.

3 . The method according to claim 1 , wherein the polymeric ligand is polyethyleneimine (PEI).

4 . The method according to claim 1 , wherein the magnetic nanoparticles comprise iron oxide.

5 . The method according to claim 4 , wherein the iron oxide is Fe 3 O 4 .

6 . The method according to claim 1 , wherein the metal seed nanoparticles comprises gold, silver, or copper.

7 . The method according to claim 1 , wherein the metal salt comprises salt of gold, silver, or copper.

8 . The method according to claim 1 , further comprising:

controlling the synthesizing of the colloidal particles to a width from 10 nm to 150 nm.

9 . The method according to claim 1 , further comprising:

utilizing the plasmonic structure in a biomedical application.

10 . A method of forming magnetic/plasmonic hybrid structures comprising:

synthesizing colloidal magnetic nanoparticles;

modifying the magnetic nanoparticles in a solution of a polymeric ligand;

binding metal seed nanoparticles to the surface of the magnetic nanoparticles;

performing a seed-mediated growth on the metal seed nanoparticles by reducing a metal salt in solution to form the magnetic/plasmonic hybrid structures; and

mediating and confining the seeded growth of the metal on the magnetic nanoparticles with the polymeric ligand, the polymeric ligand forming a deformable and permeable polymer shell on the magnetic nanoparticles that suppresses a deposition of metal atoms and limit growth of the metal atoms along a radial direction.

11 . A method of forming magnetic/plasmonic hybrid structures comprising:

synthesizing colloidal magnetic nanoparticles;

modifying the magnetic nanoparticles in a solution of a polymeric ligand;

binding metal seed nanoparticles to the surface of the magnetic nanoparticles;

performing a seed-mediated growth on the metal seed nanoparticles by reducing a metal salt in solution to form the magnetic/plasmonic hybrid structures, and

wherein the magnetic/plasmonic hybrid structures comprises a plurality of the magnetic/plasmonic hybrid structures, further comprises:

magnetically assembling the plurality of the magnetic/plasmonic hybrid structures into plasmonic chains in an active transparent display or an anti-counterfeiting device.