We have determined that a biological molecule can be physically immobilized on a polymer containing an azobenzene (azopolymer) using irradiating light. We immobilized antibodies and antigens on the surface of an azopolymer coated glass slide (antibody array) to establish "on-chip ELISAs". The assays used the flat-surface of a glass slide and could be applied to both sandwich and competitive ELISAs. The sensitivity and accuracy of the on-chip ELISA were similar to a conventional ELISA using a polystyrene plate. Using the assay system, we proved that representative oxidative-biomarkers could be simultaneously measured from uL of urine. That should realize low-cost study on animal or human, and accelerate development of health-promoting foods. So, this new concept antibody array has promising applications in proteomic studies, and could be used to examine biomarkers to investigate health-promoting food.