A method and sensor for the detection of luminescence radiation generated by at least one luminophore is disclosed. In the context of the present invention the biosensor comprises a grid (120) defined as arrays of apertures with the apertures having a first dimension below and a second dimension above the diffraction limit of the excitation light (102) in a medium, a polarizer (115), and luminophores (117) positioned in a volume selected from the group consisting of: the volume inside the apertures of the grid (120), the volume in between the array of slits (120) and the polarizer (115) and a volume that extends into the polarizer (115), wherein the grid (120) providing a transmission axis extending in a first direction and the polarizer (115) providing a transmission axis extending in a second direction, the first direction and the second direction being substantially perpendicular with respect to each other, wherein the excitation radiation (102) is polarized such that it is substantially suppressed by one of the at least one grid (120) and polarizer (115) and substantially not suppressed by the other of the at least one grid (120) and polarizer (115).