Single-molecule mass spectrometry in solution using a solitary nanopore.
We introduce a two-dimensional method for mass spectrometry in solution that is based on the interaction between a nanometer-scale pore and analytes. As an example, poly(ethylene glycol) molecules that enter a single alpha-hemolysin pore cause distinct mass-dependent conductance states with characteristic mean residence times. The conductance-based mass spectrum clearly resolves the repeat unit of ethylene glycol, and the mean residence time increases monotonically with the poly(ethylene glycol) mass. This technique could prove useful for the real-time characterization of molecules in solution.
Robertson
Joseph W F
JW
Electronics and Electrical Engineering Laboratory, Semiconductor Electronics Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8120, USA.
Rodrigues
Claudio G
CG
Stanford
Vincent M
VM
Rubinson
Kenneth A
KA
Krasilnikov
Oleg V
OV
Kasianowicz
John J
JJ
D001427:Bacterial Toxins / Q000737:chemistry; D004553:Electric Conductivity; D006460:Hemolysin Proteins / Q000737:chemistry; D008970:Molecular Weight; D049329:Nanostructures / Q000737:chemistry*; D011108:Polymers; D012996:Solutions / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors
D001427:Bacterial Toxins; D006460:Hemolysin Proteins; D011108:Polymers; D012996:Solutions; C021091:staphylococcal alpha-toxin