Fabricating Efficient White-Light-Emitting Ultra-Small Gold Nanoparticles via a Supramolecular Strategy

Low quantum yield (QY), short luminescent lifetimes, and monotonous luminescent colors have severely limited the development of luminescent nanomaterials. Gold nanoclusters (AuNCs) stand out among luminescent nanomaterials, thanks to their ultra-fine size, superior luminescent performance, and photostability. Herein, we prepared ultra-small gold nanoparticles with uniform orange phosphorescence through a one-pot synthesis. Several types of FGGC@AuNCs were formed in this way, using N-terminal phenylalanine–glycine–glycine–cysteine (FGGC) peptides as ligands. By virtue of the supramolecular forces between cucurbit[7]urils (CB7) and FGGC ligands, we promoted the QY of the FGGC@AuNCs from 3.5% to 25.4% and prolonged the phosphorescent lifetime from 5.6 to 9.6 µs. Blue fluorescent Trp@AuNCs with a QY of 45.3% were then used to fabricate a tunable luminescent assembled solution with FGGC@AuNCs/CB7 assemblies based on a supramolecular strategy, with the notable result of standard white-light emission with a QY of 22.6%. Interestingly, the luminescent color of the assembled solution exhibited a sensitive response to temperature and excitation wavelength. Moreover, the assembled solution was used to fabricate multicolor tunable polyvinyl alcohol films with white-light emission, facilitating the application of AuNCs in white-light-emitting diode devices.