The invention relates to a membrane and a sensor with the membrane. Specifically, a membrane, especially for application in a sensor, which membrane includes a biocidal effect. The membrane comprises one or more components of the group consisting of: silver nano particles encapsulated in amphiphilic, core, shell structures, antimicrobial silanes, polymers with an antimicrobial end group, polyquads with modified end groups, and biocidally acting block copolymers. The membrane is resistant against aggressive agents, for example, corrosive or oxidizing cleaning agents, in the case of sterilizing, in the case of autoclaving, in the case of thermal loading and/or in the case of mechanical loading.