Enhanced Fluorescence for Bioassembly by Environment‐Switching Doping of Metal Ions

Abstract

The self‐assembly of cyclodipeptides composed of natural aromatic amino acids into supramolecular structures of diverse morphologies with intrinsic emissions in the visible light region is demonstrated. The assembly process can be halted at the initial oligomerization by coordination with zinc ions, with the most prominent effect observed for cyclo‐dihistidine (cyclo‐HH). This process is mediated by attracting and pulling of the metal ions from the solvent into the peptide environment, rather than by direct interaction in the solvent as commonly accepted, thus forming an “environment‐switching” doping mechanism. The doping induces a change of cyclo‐HH molecular configurations and leads to the formation of pseudo “core/shell” clusters, comprising peptides and zinc ions organized in ordered conformations partially surrounded by relatively amorphous layers, thus significantly enhancing the emissions and allowing the application of the assemblies for ecofriendly color‐converted light emitting diodes. These findings shed light into the very initial coordination procedure and elucidate an alternative mechanism of metal ions doping on biomolecules, thus presenting a promising avenue for integration of the bioorganic world and the optoelectronic field.

Self‐Assembled Peptide Nano‐Superstructure towards Enzyme Mimicking Hydrolysis

“…[10h, 17] MD simulations can be powerful tools in providing insights into molecular self-assembly by analyzing the initial nucleation of molecules in different environments. [18] Here,w eperformed multiple multi-ns explicit solvent MD simulations in CHARMM [19] to investigate the initial stages of cyclo-HH self-assembly in the presence of Zn 2+ and iodide ions.Across all simulations,visual inspection confirmed that disordered aggregates of cyclo-HHmolecules were reformed, indicating that the cyclo-HHmolecules were not trapped in al ocal energetic minimum in ag iven simulation and facilitated higher-order structures.W ithin the simulations,o rdered antiparallel and parallel configurations of cyclo-HH dimers were observed, with the former being the predominant configuration (Figure S9, Table S1), in line with the crystallographic data (Table S2). According to the time-evolution structural analysis of the antiparallel configurations (Figure S9, Table S1), the elementary unit Scheme 1.…”

Modification of a Single Atom Affects the Physical Properties of Double Fluorinated Fmoc-Phe Derivatives

“…Fmoc-3,4F-Phe and Fmoc-3,5F-Phe were computationally modeled independently for use as initial structures in MD simulations, described in the next section, analogously to refs [52,53]. For each system, 36 monomers (either Fmoc-3,4F-Phe or Fmoc-3,5F-Phe) were embedded in a 40 × 40 × 60 Å 3 grid within a 90 × 90 × 90 Å 3 water box, with an equal spacing of approximately 20 Å between each monomer and random configurations and orientations.…”

“…The random configurations were extracted from short simulations of each monomer at infinite dilution. The derivative concentration within each system was higher than the concentration used in the experimental studies, aiming to artificially accelerate the self-assembly within the frame of the simulations [52,53].…”

“…The self-assembly of Fmoc-3,4F-Phe and Fmoc-3,5F-Phe were independently investigated through MD simulations analogously to refs [52,53]. Prior to the execution of MD simulations, the simulation systems were first energetically minimized and equilibrated.…”

Theoretical Model for Spectroscopic Study of Cu+2, Co+2, and Fe+3 Dissolved in Ethanol with A Different Concentrations

“…Another's investigated the effect of metal ions on zeta potential [24] and the evolution of the structural and electrical properties of containing for the metal ion [25]. At the moment, some research dope the metal ions with some chemical compounds and study the influence on some physical properties [26,27]. But most research absences a theoretical work that summarizes the behavior of the metal ions spectra to be a reference.…”