US Patent 7969079 - Membrane sensor for CNTs
This patent from Harvard has priority going back to 2002 and teaches a nanotube sensor device. Claim 1 reads:
1. A carbon nanotube device comprising:
a free-standing membrane peripherally supported by a support structure and including an aperture extending through a thickness of the membrane with the aperture disposed at a membrane location directing a liquid through the aperture;
at least one carbon nanotube extending across the aperture on a front surface of the membrane and accessible from a back surface of the membrane and a connection from the carbon nanotube to an electrical circuit, sensing by the nanotube as species in a liquid pass through the aperture in the membrane.