A "nanonecklace" synthesized from monofunctionalized gold nanoparticles.

Gold nanoparticles with a single carboxylic acid group on the surface were prepared from a solid phase place exchange reaction and then coupled to polylysine using an in situ activation agent, diisopropylcarbodiimide (DIPCDI). The covalent amide bond linkage between the nanoparticles and polylysine and the ring closure of the polylysine chain have led to the formation of a nanoparticle/polymer hybrid material with "nanonecklace" structures.