Single-molecule interfacial electron transfer dynamics manipulated by external electric current

摘要

Interfacial electron transfer (IET) dynamics in 1,1'-dioctadecyl-3, 3, 3',3'-tetramethylindodicarbocyanine (DiD) dye molecules / indium tin oxide (ITO)film system have been probed at the ensemble and single-molecule level byrecording the change of fluorescence emission intensity. By comparing thedifference of the external electric current (EEC) dependence of lifetime andintensity for enambles and single molecules, it is shown that thesingle-molecule probe can effcienly demonstrate the IET dynamics. The backwardelectron transfer and electron transfer of ground state induce the singlemolecules fluorescence quenching when an EEC is applied to ITO film.