Biosensor system based on recognition induced birefringence (RIB)

Label-free biosensor system comprising:

• an anisotropically microstructured elastomeric sensor substrate having elevated regions and depressions on at least one side, wherein the distance between the elevated regions is in the range from 0.5 to 100 μm and the height of the elevated regions is in the range from 1 to 500 μm, wherein either (a) said sensor substrate is made of an elastomer, and is further coated, at least on the top surface thereof, with a polymeric material selected from poly(ethylene oxide), poly(propylene oxide), poly(glycidol) and copolymers thereof, said polymeric material being bound to the sensor substrate either covalently or through ionic interactions, complexes or hydrogen bridges, or (b) said sensor substrate is composed in its entirety of a polymeric material selected from poly(ethylene oxide), poly(propylene oxide), poly(glycidol) or copolymers thereof or a hydrogel-forming polymer, and wherein, only on the elevated regions, biorecognition molecules are covalently bound via said polymeric material or directly to said sensor substrate, respectively.