Chemical and biological sensor using an ultra-sensitive force transducer

A sensor for a selected target molecule, comprising:

• a cantilever having attached chemical groups, disposed in solution and in a magnetic field;
• and
• one or more magnetic structures, disposed in said solution, wherein said structures have been chemically modified to have a selective binding response relative to said attached chemical groups on said cantilever in the absence of said target molecule, and a different selective binding response relative to said attached chemical groups on said cantilever in the presence of said target molecule.

A sensor for a selected target molecule, wherein said selected target molecule has, or may be modified to have, a net charge or dipole moment, comprising:

• a cantilever having attached chemical groups, disposed in an electric field, wherein said attached chemical groups selectively bind to said selected target molecule;
• and
• means for monitoring the deflection of said cantilever.

A sensor for a selected target species, comprising:

• a cantilever having attached chemical groups, disposed in an electric field;
• and
• one or more charged or dipolar structures, disposed in said electric field, wherein said structures have been chemically modified to have a selective binding response relative to said attached chemical groups on said cantilever in the absence of said target species, and a different selective binding response relative to said attached chemical groups on said cantilever in the presence of said target species.