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.

Rethreading Design of Ratiometric roGFP2 Mimetic Peptide for Hydrogen Peroxide Sensing

“…The diphenylalanine motif here, which coincides with the core recognition motif of Alzheimer’s β-amyloid polypeptide, − was designed to increase the amphiphilicity and assembly properties of the tetrapeptide . Histidine was assigned at the terminal, which may facilitate the production of multicolor emissions as we previously studied . To conclude, we intend to utilize the assembly induced emissions of reducedand oxidizedtetrapeptide to produce ratiometric emissions.…”

“…We noticed that compared to the CD spectra of the thiol from, the proportion of the antiparallel β-sheets of the disulfide form of the tetrapeptide increased obviously. As the peptide nanostructure is usually amorphous making it challenging to get experimental crystal data under physiological conditions, , we then performed coarse-grained molecular dynamics (CG-MD) simulations of the roGFP2 mimetic tetrapeptide as well as the oxidic disulfide form of the tetrapeptide to gain insights into the structural basis of ratiometric fluorescence at a molecular level. The CG-MD results revealed that both the thiol and the disulfide form of the tetrapeptide can self-assemble into clusters and the clusters further merge into the nanosphere within 1000 ns (Figure c and Supplementary Figures S14 and S15).…”

Quantitative Ratiometric Biosensors Based on Fluorescent Ferrocene-Modified Histidine Dipeptide Nanoassemblies

“…Molecular dynamics simulations were performed as we previously reported . In detail, the coarse-grained molecular dynamics (CG-MD) simulations were performed using GROMACS 2019.6 software.…”

“…Herein, we design a ferrocene-modified histidine dipeptide ( f- HH dipeptide) as the histidine residue can construct color-tunable peptide nanostructures, as shown in our previous study. , The f- HH dipeptide has a ratiometric fluorescence, of which the value was linear with the peptide concentration with a correlation range of three orders of magnitude. We expand this unique concentration-encoded emission toward a quantitative assessment of its intracellular distribution as well as the biocompatible ratiometric biosensors .…”

“…Molecular dynamics simulations were performed as we previously reported. 29 In detail, the coarse-grained molecular dynamics (CG-MD) simulations were performed using GROMACS 2019.6 software. A CG Martini 2.2 force field was selected to model the f-HH dipeptide and targeted hexapeptide.…”