Measurement of Carbon Composite Mass Across a Broad Range Using a Diamond Nanomechanical Oscillator

Mass spectrometry (MS) boasts an exceptional ability to accurately quantify molecules with complex structures, offering valuable insights for the identification and analysis of unknown molecules. With advancements in mass spectrometry using nanoelectromechanical systems (NEMS-MS) has been developed, expanding its capabilities, enabling precise measurements not only of small molecules but also of more complex structures, such as viral capsids with masses exceeding 100 MDa. These developments have been proposed as significant steps toward broadening scientific understanding.
NEMS-MS utilizes a nanomechanical oscillator to analyze the correlation between frequency shifts and changes in mass. By adjusting the dimensions of the device based on the mass range of the analyte, it has been reported to handle a mass range spanning three orders of magnitude. Recently, studies have investigated mass correction based on the position of analytes by employing the first and second mode oscillations of nano-oscillators, as well as minimum mass resolution through the analysis of Allan deviation in nanomechanical oscillators. A system with a minimum resolution of 0.6 MDa has accurately measured the mass variation of bacteriophage T5 in the presence and absence of DNA.
In this work, we fabricate a diamond nanomechanical oscillator array using semiconductor processing techniques and discuss a mass spectrometry system with a wide dynamic range that leverages the superior mechanical properties of diamond, such as high quality factor and maximum tensile strain. We also explore in-situ carbon deposition and the corresponding mass measurement techniques, and further discuss the minimum mass resolution and maximum measurable mass range achievable through the excellent material properties of diamond.