  Weighing particles above MegaDalton mass range has been a persistent
challenge in commercial mass spectrometry. Recently, nanoelectromechanical
systems-based mass spectrometry (NEMS-MS) has shown remarkable performance in
this mass range, especially with the advance of performing mass spectrometry
under entirely atmospheric conditions. This advance reduces the overall
complexity and cost, while improving the limit of detection. However, this
technique required the tracking of two mechanical modes, and the accurate
knowledge of mode shapes which may deviate from their ideal values especially
due to air damping. Here, we used a NEMS architecture with a central platform,
which enables the calculation of mass by single mode measurements. Experiments
were conducted using polystyrene and gold nanoparticles to demonstrate the
successful acquisition of mass spectra using a single mode, with improved areal
capture efficiency. This advance represents a step forward in NEMS-MS, bringing
it closer to becoming a practical application for mass sensing of
nanoparticles.
