Monitoring single-molecule reactivity on a carbon nanotube.
Using point-functionalized carbon nanotube devices, we demonstrate continuous, multihour monitoring of a single carboxylate group interacting with its immediate environment. The conductance of the nanotube device directly transduces single-molecule attachments and detachments in the presence of the carboxylate-selective reagent 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Because only one carboxylate is present in the device, it can be studied through hundreds of reactions, providing the statistical accuracy to directly determine a 12 s lifetime of the carboxy-EDC complex. An additional instability of the complex is transduced in real time and observed to have a median lifetime of 2 ms. By determining a turnover time in good agreement with bulk measurements and simultaneously illuminating additional dynamics, these results demonstrate this platform's potential for complementing optical methods in single-molecule research.
Goldsmith
Brett R
BR
Departments of Physics and Astronomy, Molecular Biology and Biochemistry, and Chemistry, University of California, Irvine, California 92697-2025, USA.
Coroneus
John G
JG
Kane
Alexander A
AA
Weiss
Gregory A
GA
Collins
Philip G
PG