Functionalised polymeric chromatography medium, comprising: at least one non-woven sheet comprising one or more polymeric nanofibers having a mean diameter of 10-1000 nm; one or more polymer chains grafted onto the one or more polymeric nanofibers, wherein the polymer chains are poly-glycerol chains comprising glycidol monomer residues or wherein the polymer chains comprise divinylsulfone monomer residues; and at least one ligand group bonded to the one or more polymer chains.