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

Science ◽  
2018 ◽  
Vol 362 (6417) ◽  
pp. 918-922 ◽  
Author(s):  
Sergio Dominguez-Medina ◽  
Shawn Fostner ◽  
Martial Defoort ◽  
Marc Sansa ◽  
Ann-Kathrin Stark ◽  
...  

Measurement of the mass of particles in the mega- to gigadalton range is challenging with conventional mass spectrometry. Although this mass range appears optimal for nanomechanical resonators, nanomechanical mass spectrometers often suffer from prohibitive sample loss, extended analysis time, or inadequate resolution. We report on a system architecture combining nebulization of the analytes from solution, their efficient transfer and focusing without relying on electromagnetic fields, and the mass measurements of individual particles using nanomechanical resonator arrays. This system determined the mass distribution of ~30-megadalton polystyrene nanoparticles with high detection efficiency and effectively performed molecular mass measurements of empty or DNA-filled bacteriophage T5 capsids with masses up to 105 megadaltons using less than 1 picomole of sample and with an instrument resolution above 100.

1998 ◽  
Vol 5 (3) ◽  
pp. 612-614
Author(s):  
Hitoshi Sakamoto ◽  
Yuji Takakuwa ◽  
Toyokazu Hori ◽  
Yoshiharu Enta ◽  
Hiroo Kato ◽  
...  

A three-electrode-lens drift tube for time-of-flight mass spectrometry (TOF-MS) has been developed for utilizing a detector to observe photon-stimulated desorption (PSD). In spite of a small detection area, the detector has a high detection efficiency and durability to reactive gas atmosphere at high pressure. The TOF-MS performance of the drift tube was examined for PSD using single-bunch-mode synchrotron radiation on a dichlorosilane (SiH2Cl2)-saturated Si(001) surface. The measured acceleration and focusing-voltage dependences of the time of flight, intensity and full width at half-maximum for the peak of H+ and Cl+ PSD ions are discussed in terms of the numerical calculations of ion trajectories and focusing characteristic of the drift tube.


Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3593 ◽  
Author(s):  
Stachiv ◽  
Gan

Micro-/nanomechanical resonators are often used in material science to measure the elastic properties of ultrathin films or mass spectrometry to estimate the mass of various chemical and biological molecules. Measurements with these sensors utilize changes in the resonant frequency of the resonator exposed to an investigated quantity. Their sensitivities are, therefore, determined by the resonant frequency. The higher resonant frequency and, correspondingly, higher quality factor (Q-factor) yield higher sensitivity. In solution, the resonant frequency (Q-factor) decreases causing a significant lowering of the achievable sensitivity. Hence, the nanomechanical resonator-based sensors mainly operate in a vacuum. Identification by nanomechanical resonator also requires an additional reference measurement on the identical unloaded resonator making experiments, due to limiting achievable accuracies in current nanofabrication processes, yet challenging. In addition, the mass spectrometry by nanomechanical resonator can be routinely performed for light analytes (i.e., analyte is modelled as a point particle). For heavy analytes such as bacteria clumps neglecting their stiffness result in a significant underestimation of determined mass values. In this work, we demonstrate the extraordinary capability of hybrid shape memory alloy (SMA)-based nanomechanical resonators to i) notably tune the resonant frequencies and improve Q-factor of the resonator immersed in fluid, ii) determine the Young’s (shear) modulus of prepared ultrathin film only from frequency response of the resonator with sputtered film, and iii) perform heavy analyte mass spectrometry by monitoring shift in frequency of just a single vibrational mode. The procedures required to estimate the Young’s (shear) modulus of ultrathin film and the heavy analyte mass from observed changes in the resonant frequency caused by a phase transformation in SMA are developed and, afterward, validated using numerical simulations. The present results demonstrate the outstanding potential and capability of high frequency operating hybrid SMA-based nanomechanical resonators in sensing applications that can be rarely achieved by current nanomechanical resonator-based sensors.


2013 ◽  
Vol 8 (01) ◽  
pp. P01015-P01015 ◽  
Author(s):  
J Pan ◽  
Y Yang ◽  
Y Tian ◽  
M Zeng ◽  
T Deng ◽  
...  

2020 ◽  
pp. 1-15
Author(s):  
Luis Abuel ◽  
Friedl Bartsch ◽  
Andrew Berry ◽  
Jean-Claude Buffet ◽  
Sylvain Cuccaro ◽  
...  

A detector upgrade was carried out on the PLATYPUS instrument dedicated to neutron reflectometry at the Australian Nuclear Science and Technology Organisation (ANSTO). The new detector, developed in the framework of a research collaboration between the ILL and ANSTO, is based on the Monoblock Aluminium Multi-tube (MAM) detector design already in use on several reflectometers and SANS instruments at the ILL. This article provides a technical description of the mechanical design and read-out electronics of the PLATYPUS detector and its commissioning on the PLATYPUS instrument. The main detector performance parameters have been measured and are presented here as well as the characterisation methods and the results of several reflectometry measurements. These measurements show an improvement in experimental data quality resulting from high positional resolution, high detection efficiency and reduced neutron scattering background in the 2.5–19 Å neutron wavelength range used in PLATYPUS instrument.


2018 ◽  
Vol 48 ◽  
pp. 1860121 ◽  
Author(s):  
Zhiwen Wen ◽  
Huirong Qi

The re-designed two-dimensional, multi-wire proportional chamber (MWPC) detector based on the [Formula: see text]He operation gas has been developed for the multifunctional reflection spectrum detection requirements in China Spallation Neutron Source (CSNS), which is under construction in Guangdong province, China. This efficient thermal neutron detector with large area (200 mm [Formula: see text] 200 mm active area), two-dimensional position sensitive (<2 mm of position resolution), high detection efficiency (>65% in the wavelength of 1.8Å) and good n/[Formula: see text] discrimination would meet some requirements in CSNS The neutron detector consists of a MWPC detector and a high-pressure gas vessel. The wire readout structures of the detector and the gas purity device have been optimized based on previous design and testing. The re-designed MWPC detector with an absorber thickness of 10 mm and 8.5 atm operating gas mixture of [Formula: see text]He and C[Formula: see text]H[Formula: see text] was constructed. Using the non-return valve manufactured by Swagelok, the gas purity device was developed to clean the water and remove gas impurities. The effective cycle time can be up to 50 min per sequence. The performance of the position resolution and the two-dimensional imaging accuracy by the traditional center of gravity readout method was studied with an X-ray radiation source and the neutron source. At the end of this year, the detector will be mounted at CSNS and studied using the neutron source.


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