Nanomechanical Spectroscopy: A novel route to label-free chemical sensing

We propose a novel spectroscopic technique in which the vibrational modes of an analyte molecule are probed directly using a nanoscale mechanical resonator. It is anticipated that such ``nanomechanical spectroscopy'' can provide a method for label free chemical sensing. We elucidate the concept of the nanomechnical spectroscope with the example of using an array of carbon nanotubes to detect a series of simple test molecules. In these examples, energy is transferred between the molecular vibrations of the analyte and specific phonon modes of the carbon nanotubes. Molecular dynamics simulations are used to explore the feasibility of this energy exchange for chemical sensing, and limits of both sensitivity and selectivity.