A method and composition for enhancing corrosion resistance, wear resistance, and contact resistance of a device comprising a copper or copper alloy substrate and at least one metal-based layer on a surface of the substrate. The composition comprises a phosphorus oxide compound selected from the group consisting of a phosphonic acid, a phosphonate salt, a phosphonate ester, a phosphoric acid, a phosphate salt, a phosphate ester, and mixtures thereof; an organic compound comprising a nitrogen-containing functional group; and a solvent having a surface tension less than about 50 dynes/cm as measured at 25° C.