We developed an improved method to chemically immobilize antibodies on a nylon surface using a styrene maleic anhydride copolymer having an aryl group, which provides hydrophobicity to the nylon surface. We applied it to a modified enzyme-linked immunosorbent assay (slip-ELISA) for the detection of cholera toxin (CT). The sensitivity of slip-ELISA for CT detection was 1,000 times higher than that of conventional methods of physical adsorption using polystyrene plates, and 10 times higher than that of the method of chemical immobilization using maleic anhydride methylvinyl ether copolymer.