Sensor element for optically detecting chemical or biochemical analytes

The invention relates to a sensor element for optically detecting chemical or biochemical analytes which may be contained in different samples. The object is to minimize the required sample volume and to allow the individual samples to be arranged relatively close together, while nevertheless achieving a high measurement accuracy. At least one interface, at which an evanescent field is formed as a result of total reflection, is formed on the sensor element. The samples are held in mutually separated cavities, and the cavities are formed inside a structured cover layer applied directly to a substrate. In this case, the layer thickness of the cover layer is at least greater than the penetration depth of the evanescent field. The cover layer consists of a fluorinated polymer, and it prevents substance exchange of the individual samples that are held in the various cavities.