Device and method for carrying out fluoresence immunotests

A device for carrying out fluorescence immunoassays by means of evanescent field excitation, the device comprising:

• an optically transparent base plate;
• a receiving region for a sample;
• a boundary surface between the base plate and the receiving region, the base plate having a refractive index greater than that of a material above the boundary surface;
• a plate covering the receiving region on a side opposite the base plate;
• a functional layer between the base plate and covering plate or in an inflow region for the sample into the receiving region, flowed through laterally or transversally by means of suction, pressure, or capillary force;
• a light source, emitting practically monochromatic light, directing light rays with a wavelength causing fluorescence of a marking substance bound to a chemical or biochemical partner of a receptor-ligand system onto the boundary surface on a side of the base plate opposite the covering plate;
• and
• a fluorescence detector disposed on the side of the base plate opposite the covering plate, the fluorescence detector disposed to detect fluorescence passing through the base plate and then passing through air to the fluorescence detector, the fluorescence detector not disposed to detect fluorescence coupled into the base plate acting as a waveguide.