A structure for verifying an effectiveness and stability of a linker in a drug delivery system and for verifying an in vivo stability, in vivo cleavability, and in vivo drug release efficiency of the linker in the drug delivery system,
- wherein the structure comprising a fluorescent probe, which replaces a drug in the drug delivery system and is linked to the linker whose effectiveness is to be verified,
- wherein the fluorescent probe consists of a fluorophore which fluoresces when the linker in the drug delivery system is cleaved or consists of a combination of the fluorophore and a spacer.