Abstract: It is intended to provide a stable novel sugar-immobilized metal nanoparticle capable of easily immobilizing a sugar chain, a method for measuring sugar-protein interaction easily and at a low cost using the same without labeling, and a method for simply recovering a protein from a sugar-protein interactant. A maltose-immobilized gold nanoparticle was obtained by binding a ligand complex, in which maltose and a linker compound had been bound to each other, to a gold nanoparticle. By adding this maltose-immobilized gold nanoparticle to a dilution series of concanavalin A, a sugar-protein interactant of maltose and ConA was formed, and red-purple color derived from a colloidal solution of maltose-immobilized gold nanoparticle disappeared. That is, sugar-protein interaction could be confirmed by visual observation without labeling.

Abstract: This invention provides a method of screening or patterning a biomaterial in terms of their specificities to sugar chains by performing real-time and comprehensive measurement of an interaction between sugar chains and the biomaterial concurrently with a very small amount of the biomaterial without labeling.