A simple approach for fabrication of optical affinity-based bioanalytical microsystem on polymeric PEN foils.

•Polyethylene naphthalate (PEN) foil is micropatterned by laser beam through a mask.•Chemical changes induced by laser beam enable covalent immobilization of biotin.•Well-based optical sensing system is composed from irradiated PEN foil.•Affinity-based assays performed on PEN foil detect human serum albumin (HSA).•Laser beam micropatterning is suitable for the development of bioassays.