Biocompatible method of functionalising substrates with inert surfaces

The disclosure relates to a biocompatible method of functionalising inert surfaces for use in biological applications. In particular, the disclosure relates to a biocompatible method of functionalising the inert surface of porous membranes and microspheres or nanospheres comprising the step of contacting the surface of the substrate with an aqueous dispersion of a construct of the structure F-S-L, where F is a functional moiety, S is a spacer selected to provide a construct that is dispersible in water (preferably it comprises a polyamide chain), and L is a diacyl or dialkyl- glycerophospholipid. Preferably, the inert surface consists of a substance selected from the group consisting of: glass, silver, polyamide, polycarbonate, polypropylene, polyethersulfone, polytetrafluoroethylene and polyvinylidene fluoride. Preferably F is a mono-, di-, tri- or oligosaccharide, a fluorophore of fluorescein or is biotin.