General and facile synthesis of robust composite nanocrystals with natural peach gum polysaccharide

Composite nanocrystal (CN) composed of inorganic nanocrystal and polymer has attracted great interest because of its attractive synergetic properties and wide applications. Herein, we present a simple and general method for the synthesis of various CNs (e.g., noble metal, magnetic, semiconductor and silver halide) based on the use of natural peach gum polysaccharide (PGP) as a capping agent. PGP with highly branched topological structure and abundant functional groups can not only induce the formation of CNs, but also endow the CNs with good aqueous dispersibility and stability. Thanks to the capping of PGP, the obtained CNs simultaneously possess small and relatively uniform size, numerous tailorable functional groups and low cytotoxicity. In addition, it is also confirmed that some CNs (e.g., PGP-Au and PGP-AgBr) can be utilized as a catalyst with high catalytic activity due to their accessible surface for substrate molecules. Considering the easy synthesis process and robust performance of CNs, this study opens up a new opportunity for scalable synthesis of applicable CNs. • A general method to synthesize composite nanocrystals (CNs) is reported. • Natural peach gum polysaccharide (PGP) is utilized as a robust capping agent. • CNs exhibit fine water-dispersibility, good colloidal stability and low cytotoxicity. • CNs possess numerous surface functional groups for further modification. • CNs with high catalytic activity can also be synthesized.