Preparación de superficies funcionalizadas de sustratos de poliestireno

The present invention describes the preparation of polystyrene surfaces chemically modified with a wide variety of functional groups. This involves a wet modification performed in two steps. The first step is the activation of the surface on creating chlorosulphonyl groups by immersing the polystyrene substrates in a chlorosulphonic acid solution at low temperatures. After washing, the modified substrate is immersed in an aqueous solution that contains a bifunctional compound, one of the functional groups being a primary aliphatic amine that serves as anchorage to the surface by means of a sulphonamide covalent bond. The second functional group is available on the modified surface and can be used to immobilize biomolecules when a covalent connection is created or to adjust surface parameters such as wettability or adhesion. The optical quality of the samples is maintained unaltered during the modification, which allows the use of the modified surfaces as an ideal tool for diagnostic assays of the ELISA or DNA chip type.