PHOTOLUMINESCENT Cu NANOPARTICLES INDUCED BY ENERGY TRANSFER ON SAPONITE NANOSHEET

Abstract

Photoluminescence (PL) of metal nanoparticles (NPs) has historically been investigated with their films, where PL is enhanced by surface plasmon resonance of the NPs themselves. In contrast, it is difficult to observe the PL in colloidal dispersion probably due to too long interparticle distance. In the present study, we observed the PL by introducing Förster resonance energy transfer from acridine orange adsorbed on saponite nanosheets, where Cu NPs were synthesized directly. In the presence of the Cu NPs, the PL spectra were dramatically changed. The PL of the Cu NPs was confirmed by temperature dependency of the PL spectra. It was also found that lifetime of AO was shortened accompanying with an additional PL component, which was ascribed to the Cu NPs. In addition, sufficient amount of the Cu NPs was distributed in the range of <20 nm from the nearest Cu NP. Therefore, it was concluded that the Cu NPs showed the PL by the energy transfer from acridine orange, which was enhanced by the surface plasmon resonance of the Cu NPs nearby.