Electron transfer-induced blinking in Ag nanodot fluorescence.
Various single-standed DNA-encapsulated Ag nanoclusters (nanodots) exhibit strong, discrete fluorescence with solvent polarity-dependent absorption and emission throughout the visible and near-IR. All species examined, regardless of their excitation and emission energies, show similar µs single-molecule blinking dynamics and near IR transient absorptions. The polarity dependence, µsec blinking, and indistinguishable µsec-decaying transient absorption spectra for multiple nanodots suggest a common charge transfer-based mechanism that gives rise to nanodot fluorescence intermittency. Photoinduced charge transfer that is common to all nanodot emitters is proposed to occur from the Ag cluster into the nearby DNA bases to yield a long-lived charge-separated trap state that results in blinking on the single molecule level.
Patel
Sandeep A
SA
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400.
Cozzuol
Matteo
M
Hales
Joel M
JM
Richards
Chris I
CI
Sartin
Matthew
M
Hsiang
Jung-Cheng
JC
Vosch
Tom
T
Perry
Joseph W
JW
Dickson
Robert M
RM