High-speed multiple-mode mass-sensing resolves dynamic nanoscale mass distributions

• Main Authors: Cermak, Nathan (Contributor), Olcum, Selim A. (Author), Manalis, Scott R (Author), Wasserman, Steven (Author)
• Other Authors: Massachusetts Institute of Technology. Computational and Systems Biology Program (Contributor), Massachusetts Institute of Technology. Department of Biological Engineering (Contributor), Massachusetts Institute of Technology. Department of Mechanical Engineering (Contributor), Koch Institute for Integrative Cancer Research at MIT (Contributor), Olcum, Selim (Contributor), Manalis, Scott R. (Contributor), Wasserman, Steven Charles (Contributor)
• Format: Article
• Language: English
• Published: Nature Publishing Group, 2015-05-12T18:32:59Z.
• Subjects: Article
• Online Access: Get fulltext

 Simultaneously measuring multiple eigenmode frequencies of nanomechanical resonators can determine the position and mass of surface-adsorbed proteins, and could ultimately reveal the mass tomography of nanoscale analytes. However, existing measurement techniques are slow (<1 Hz bandwidth), limiting throughput and preventing use with resonators generating fast transient signals. Here we develop a general platform for independently and simultaneously oscillating multiple modes of mechanical resonators, enabling frequency measurements that can precisely track fast transient signals within a user-defined bandwidth that exceeds 500 Hz. We use this enhanced bandwidth to resolve signals from multiple nanoparticles flowing simultaneously through a suspended nanochannel resonator and show that four resonant modes are sufficient for determining their individual position and mass with an accuracy near 150 nm and 40 attograms throughout their 150-ms transit. We envision that our method can be readily extended to other systems to increase bandwidth, number of modes, or number of resonators.