Single-particle mass spectrometry with arrays of frequency-addressed nanomechanical resonators

Abstract

One of the main challenges to overcome to perform nanomechanical mass spectrometry analysis in a practical time frame stems from the size mismatch between the analyte beam and the small nanomechanical detector area. We report here the demonstration of mass spectrometry with arrays of 20 multiplexed nanomechanical resonators; each resonator is designed with a distinct resonance frequency which becomes its individual address. Mass spectra of metallic aggregates in the MDa range are acquired with more than one order of magnitude improvement in analysis time compared to individual resonators. A 20 NEMS array is probed in 150 ms with the same mass limit of detection as a single resonator. Spectra acquired with a conventional time-of-flight mass spectrometer in the same system show excellent agreement. We also demonstrate how mass spectrometry imaging at the single-particle level becomes possible by mapping a 4-cm-particle beam in the MDa range and above.

Neutral mass spectrometry of virus capsids above 100 megadaltons with nanomechanical resonators

“…The effect of particle stiffness on frequency was negligible in our case (19). With an array of 20 resonators multiplexed in time, an increase of more than an order of magnitude in capture cross-section (and hence detection efficiency) could be obtained without degrading the mass resolution (20,21), in our case a few 100 kDa (22).…”

Resolving heterogeneous high-mass macromolecular machineries by Orbitrap-based single particle charge detection mass spectrometry

“…Whereas a multitude of ions is detected in every scan, almost all ions in the sample have a unique m/z and are thus detected and resolved as single ions. The multiplicity of ions in all scans substantially improves the duty cycle compared to measurements of a single ion at a time, as has been noted for other single particle MS approaches 19 . With the ion sampling described here, thousands of 'single ions' can be detected within minutes.…”

“…An attractive alternative may come from measuring one particle (or ion) at a time, thereby avoiding the problematic convolution of signals that stem from insufficient resolving power [17][18][19][20][21][22][23][24][25][26][27] . When such single-particle detection approaches can be combined with an independent measure of the charge of ions, or when masses can be estimated using entirely different physical principles that circumvent the need to work with multiply charged ions, this opens up the door to bona fide single-particle mass spectrometry measurements.…”

“…In NEMS-MS, single particles are deposited on a NEMS resonator, whose vibrational frequency is affected by the absorption of a single particle. The mass of the impacting particle can be calculated directly from the frequency shift that the resonator experiences 19,[23][24][25] . In CD-MS, the mass is calculated by measuring the m/z ratio and charge separately, typically by oscillating the particle in a cone trap through a conductive detection tube 17,26,27 .…”

Stress-Controlled Frequency Tuning and Parametric Amplification of the Vibrations of Coupled Nanomembranes

“…In general, such a stress control may allow for modifying not only the mechanical resonance frequencies and quality factors, but also the nonlinear response of the resonators [1,[11][12][13]. Such a tunability is particularly interesting for arrays consisting of multiple resonators, for instance to match or enhance their collective response and sensing capabilities [14,15], to engineer and investigate complex collective dynamics [16][17][18], or to coherently manipulate phonons between them [19][20][21][22][23][24][25].Suspended drum-shaped resonators, made of low loss material such as silicon nitride and possessing high mechanical quality factors, can be efficiently coupled to electromagnetic fields, whether in the optical or microwave/radiofrequency domains [26][27][28][29][30][31][32][33]. Having multiple such membrane resonators [34-37] simultaneously interacting with cavity fields opens for a number of exciting applications, e.g., collectively enhanced optomechanics [38][39][40][41], optomechanical synchronization [42], phonon transport [43,44] or entanglement and multimode squeezing generation [45][46][47][48][49].We investigate here the tuning of the linear and nonlinear mechanical properties of suspended silicon nitride square drums by the application of a piezoelectrically controlled force to the chip supporting the drums.…”