A sensor for ultra-low concentration chemical recognition comprises a force transducer, a tip coupled to this force transducer, and a substrate positioned for force interaction with the force transducer tip, where the substrate and tip are chemically modified with antigens, antibodies, nucleic acids,...http://www.google.ca/patents/US5372930?utm_source=gb-gplus-sharePatent US5372930 - Sensor for ultra-low concentration molecular recognition
