Apparatus and method for ultrasensitive nanoelectromechanical mass detection

摘要

The invention relates to the application of the techniques of nanoelectromechanical systems (NEMS) to ultrasensitive mass detection. A pulsed flux of atoms is adsorbed onto the surface of a 32.8 MHz nanomechanical resonator within an ultrahigh vacuum environment. The mass-induced frequency shifts from these adsorbates are then used to demonstrate a mass sensitivity of ~1.46x106 Daltons (Da). For resonators operating up to frequencies of 72 MHz, inverse mass responsivities as small as ~8x10-20 grams/Hz (5x104 Da/Hz) are obtained. Our results offer a new approach to ultrahigh resolution mass spectrometry of individual, electrically-neutral macromolecules with clear prospects for single Dalton sensitivity.