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

TL;DR

This study investigates how external electric current influences interfacial electron transfer in dye-ITO systems, revealing single-molecule fluorescence quenching mechanisms through ensemble and single-molecule fluorescence measurements.

Contribution

It demonstrates the effectiveness of single-molecule fluorescence as a probe for IET dynamics under external electric current in dye-ITO interfaces.

Findings

Single-molecule fluorescence reveals IET dynamics more effectively than ensemble measurements.

External electric current induces fluorescence quenching via backward and ground-state electron transfer.

Single-molecule probes can distinguish different electron transfer pathways in IET processes.

Abstract

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 by recording the change of fluorescence emission intensity. By comparing the difference of the external electric current (EEC) dependence of lifetime and intensity for enambles and single molecules, it is shown that the single-molecule probe can effcienly demonstrate the IET dynamics. The backward electron transfer and electron transfer of ground state induce the single molecules fluorescence quenching when an EEC is applied to ITO film.