Photoluminescence of Diphenylalanine Peptide Nano/Microstructures: From Mechanisms to Applications

Diphenylalanine (Phe-Phe, FF) molecules, which can self-assemble into highly ordered nano/microstructures, have increasingly aroused intense interests due to their special optical properties. In this review, recent advances in photoluminescence (PL) of supramolecular architectures of FF-based peptide and the underlying mechanisms are highlighted. Mainly deep ultraviolet emission at around 285 nm and/or blue emission at approximate to 450 nm are observed in various FF peptide structures and its derivatives, which are primarily interpreted by quantum confinement effects, shallow radiative traps, and electron delocalization via hydrogen bonds in beta-sheet structures. Furthermore, current applications of such fluorescent peptide nano/microstructures are also reviewed here, e.g., probing the number of water molecules confined in FF, temperature sensing, and visualization of deep ultraviolet beam. Yet, the PL mechanism is still under fierce debate and the application based on fluorescence is constantly under exploration. Thus, this review is endeavored to boost future explorations on the PL of the bioinspired FF peptide nano/microstructures.