Functionalization of gold nanospheres and nanorods by chitosan oligosaccharide derivatives

Two new chitosan oligosaccharide derivatives are synthesized for the surface modification of gold nanospheres and nanorods (see figure). These biopolymers have multiple thiols (ca. 6 thiols per polymer molecule) (polymer I) or oleic acids (polymer II) for the effective anchoring to the nanoparticle surface, as well as primary amine groups for further bioconjugation.