Nanoscale Mass Spectrometer for Single Molecule Detection

Boy, moment I finish writing about the problems with Mass Spectroscopy (MS) I see this report about single molecule nanomechanical mass spectrometry. Reminded me of a comment I saw in a report about reproducibility of MS methods:

“— a difficult challenge affecting evaluation of many new technologies — the problem of a moving target in which, from study to study, technical features change. For serum proteomics technology, such features include type of mass spectroscopy machine, sample application, washing, chip surface, and patients.”

But for time being, forget about the realities of real life and dream what a proteome wide study of single cell can deliver in terms of our understanding of biology. The report uses Nanoelectromechanical systems (NEMS) devices for detecting mass of proteins. NEMS are nanosized beam that vibrate at very high frequency and any small increase in mass, say by adsorption of proteins, changes the vibrational frequency proportional to mass. For NEMS-MS, protein is ionized as usual and then transported to the NEMS where the mass is measured as small blips in frequency. The 2nd generation of the technology will be able to distinguish not only the mass change but also the position on the beam where proteins adsorb further enhancing the capabilities of the NEMS-MS.

The current study is just a proof-of-principle demonstration but it’s the potential of the technology that is exciting:

  • Sensitivity: 1 Da mass discrimination
  • Exceptionally Large Dynamic Range: NEMS are capable of measuring mass of million Da or more with sensitivity of 1 Da
  • Multiplexing: Using nanofabrication techniques it is possible to fabricate large number of NEMS on single chips. A modest number of 1000 devices will allow 10 million molecules to be analyzed in 100 seconds

Moving this proof-of-concept device to real life laboratory for everyday analysis of biological/chemical samples will require surmounting tremendous challenges but like I said in my previous post – 1% inspiration and 99% perspiration. Let the hard work begin!


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