Effects of silver nanoclusters on the spectral properties for fluorescein isothiocyanate with restrained photobleaching

Ligand protected noble metal nanoclusters have unique physical and chemical properties and the effects of metal nanoclusters on photoluminescence and energy transfer process for fluorescence molecules are still unclear. In this work, we prepared silver nanoclusters (Ag NCs) with different emission wavelengths (blue, green and red emission) and investigated the energy transfer process between Ag NCs and fluorescein isothiocyanate (FITC). The photoluminescence of FITC can be regulated by the Ag NCs due to various electrons transfer and energy transfer processes between Ag NCs and FITC. The FITC can serve as electrons donor or acceptor which determines the electrons transfer direction between FITC and Ag NCs with different emissions. Astonishingly, the photobleaching of FITC can be effectively inhibited after interacting with Ag NCs, which will surely be of profound significance to the application of FITC.