Single-molecule imaging and spectroscopy using fluorescence and surface-enhanced Raman scattering.
We extended single molecule fluorescence imaging and time-resolved fluorometry from the green to the violet-excitation regime to find feasibility of detecting and identifying fluorescent analogs of nucleic-acid bases at the single-molecule level. Using violet excitation, we observed fluorescent spotsfrom single complexes composed of a nucleotide analogue and the Klenow fragmentof DNA polymerase I. Also, we implemented Raman imaging and spectroscopy of adenine molecules adsorbed on Ag colloidal nanoparticles to find feasibility of identifying nucleic-acid bases at the single-molecule level. Surface enhanced Raman scattering (SERS) of adenine molecules showed an intermittent on-and-off behavior called blinking. The observation of blinking provides substantial evidence for detecting single adenine molecules.
Joint Research Center for Atom Technology (JRCAT), 1-1-4 Higashi, Tsukuba, Ibaraki, 305-0046 Japan.
M
M
Ishikawa
Y
Y
Maruyama
J-Y
JY
Ye
M
M
Futamata
Klenow fragment; TNP-ATP; adenine; fluorescence; silver particles; single molecule imaging; surface-enhanced Raman scattering