Color‐Tunable Fluorescent Hierarchical Nanoassemblies with Concentration‐Encoded Emission

Abstract Cephalopods possess a dynamic coloration behavior to change their iridescence due to the concentration‐induced optical properties of chromatophores and hierarchical assembly of reflectin. However, cephalopods rarely have iridescence in the darkfield. It would be interesting to develop color‐tunable fluorescent hierarchical nanoassemblies with concentration‐encoded emission. Herein, to construct the bioavailable fluorophore with dynamic coloration properties, a histidine‐rich peptide is designed, which can self‐assemble into hierarchical nanoassemblies stabilized by hydrogen bonds and π–π stacking interactions. The peptidyl nanoassemblies emit fluorescent iridescence, encompassing the blue to orange region due to the assembly‐induced emission. The fluorescence of histidine‐rich peptides is color‐tunable and reversible, which can be dynamically controlled in a concentration‐encoded mode. Due to the coloration ability of histidine‐rich peptides, fluorescent polychromatic human cells are developed, highlighting its potential role as a fluorescent candidate for future applications such as bioimaging, implantable light‐emitting diodes, and photochromic camouflage.