Synthesis of size tunable gold nanoparticles polymeric hybrid based on molecular nanocages

A gold nanoparticles (NPs) polymeric hybrid was prepared through the reaction between HAuCl₄ and polyamide network polymer (PNP). The PNP has three-dimensional `nanocage´ structures and reactive amino groups incorporated in the molecular cages, so that the gold NPs can be in situ synthesised and fixed in the molecular nanocages. Owing to the volume confinement effect and the protection of the molecular nanocages, the size and the stability of the gold NPs can be controlled in a better manner. In addition, the size of the gold NPs can be tuned by changing the quantity of the precursor of the gold NPs encapsuled in the cages. Through this strategy, gold NPs with average diameters at 13.32, 11.41, 6.25 and 3.23 nm, were synthesised. These size tunable gold NPs polymeric hybrids may have a wide range of applications in many fields such as biomedicine, catalysis and optoelectronics.