Patent ID: 8810787

Claim:
An apparatus comprising: a membrane having a first and a second major surface and having a membrane-penetrating nanostructure between the first and second major surfaces, the membrane-penetrating nanostructure having an inner surface, the membrane being coated with metal on its first major surface and its second major surface and on the inner surface of the membrane-penetrating nanostructure, the metal coated on the inner surface of the membrane-penetrating nanostructure being continuous with the metal coated on the first major surface and the metal coated on the second major surface, a source of electromagnetic radiation that impinges radiation on the membrane-penetrating nanostructure in the direction of the first major surface, means for translocating molecules through the membrane-penetrating nanostructure, and a detection unit for detecting electromagnetic radiation that exits from the membrane-penetrating nanostructure away from the second major surface, transmission of electromagnetic radiation through the membrane-penetrating nanostructure being at least by excitation of surface plasmon polaritons in the membrane-penetrating nanostructure, wherein the membrane-penetrating nanostructure is further equipped with a field confining structure that creates an electromagnetic hotspot.