Indexed on: 25 Jan '17Published on: 25 Jan '17Published in: ACS Nano
Understanding photoinduced electron transfer (PET) mechanism is vital to improving the photoelectric conversion efficiency for solar energy materials and photosensitization systems. Herein we visually demonstrated the PET process by real-time monitoring the photoinduced chemical transformation (PICT) of para-aminothiophenol (p-ATP), an important SERS signal molecule, to 4,4'-dimercaptoazobenzene (DMAB) on single silver nanoparticles (AgNPs) with a localized surface plasmon resonance (LSPR) spectroscopy coupled dark-field microscopy. The bidirectional LSPR scattering spectral shifts bathochromically at first and hypsochromically then, which were caused by the electron transfer delay of p-ATP, disclosed the PET path from p-ATP to O2 through AgNPs during the reaction, and enabled us to digitalize the corresponding electron loss and gain on the surface of AgNP at different time periods. This visualized PET process could provide a simple and efficient approach to explore the nature of PET, and help to interpret the SERS mechanism in terms of p-ATP.