A nanosensor for detecting molecule characteristics includes a membrane having an opening configured to permit a charged carbon nanotube to pass but to block a molecule attached to the carbon nanotube. The opening is filled with an electrolytic solution. An electric field generator is configured to generate an electric field relative to the opening to drive the charged carbon nanotubes through the opening. A sensor circuit is coupled to the electric field generator to sense current changes due to charged carbon nanotubes passing into the opening, and to bias the electric field generator to determine a critical voltage related to a force of separation between the carbon nanotube and the molecule.