Phthalocyanine‐Triggered Helical Dipeptide Nanotubes with Intense Circularly Polarized Luminescence

Abstract

Nanotubes with circularly polarized luminescence (CPL) are attracting much attention due to many potential applications, such as chiroptical materials, displays, and sensing. However, it remains a challenge to change the assemblies of ordinarily molecular building blocks into CPL supramolecular nanotubes. Herein, the regulation of quite common dipeptide (Fmoc‐FF) assemblies into unprecedented helical nanotubes exhibiting intense CPL is reported by simply doping a few phthalocyanine (octakis(carboxyl)phthalocyaninato zinc complex (Pc)) molecules. Interestingly, altering the Fmoc‐FF/Pc molar ratios over a wide range cannot change the nanotubes structures according to transmission electron microscopy (TEM) and atomic force microscope (AFM) measurements. Although molecular dynamics simulations suggest that the noncovalent interactions between Fmoc‐FF and Pc are quite weak, few Pc molecules can still change the secondary structures of a large number of Fmoc‐FF assemblies, which hierarchically form helical supramolecular nanotubes with long‐range ordered molecular packing, leading to intense CPL signals with large luminescence dissymmetry factor (glum = 0.04). Consequently, the chiral reorganization of Fmoc‐FF assemblies is dependent on the coassembly between Pc molecule and Fmoc‐FF supramolecular architectures. These results open the possibility for the fine‐tuning of helix and supramolecular nanotubes with CPL properties by using a small number of cofactors.

Nanotubes and water-channels from self-assembling dipeptides

“…The authors envisaged potential applications in biomedicine or photocatalysis. 93 Fmoc-Lys-Phe-OMe was also reported to self-assemble into NTs when templated by addition of anionic heparin. 94…”

“…The authors envisaged potential applications in biomedicine or photocatalysis. 93 Fmoc-Lys-Phe-OMe was also reported to self-assemble into NTs when templated by addition of anionic heparin. 94 Phe-Phe has been N-capped with chromophores Cy-3 and Cy-5 to form NTs that accumulated selectively in the mitochondria of human-carcinoma cells, whose extremely negative inner membrane potential [(DC m ) cancer E À220 mV] enabled their assembly leading to apoptosis.…”

Biomolecule‐Based Circularly Polarized Luminescent Materials: Construction, Progress, and Applications

“…Jiang et al synthesized CPL spiral nanotubes composed of dipeptide (Fmoc-FF)doped phthalocyanine (octakis(carboxyl)phthalocyanine zinc complex (Pc)) molecules, which provided a new way to regulate the supramolecular structure of dipeptides. [68] Xin et al studied the assembly of atomically precise silver NCs (Ag 9 -NCs, [Ag 9 (mba) 9 ] where H 2 mba = 2-mercaptobenzoic acid) and peptide DD-5, which showed CPL and realized temperature sensing and arginine detection. [69] Yang et al demonstrated opposite CPL signals at different pH values by characterizing the co-assembly process of tolane-substituted Phe-Phe dipeptides and 1,2-diaminoethan at different pH values.…”

Bioinspired porphyrin–peptide supramolecular assemblies and their applications

“…116 Some of them can be assembled into nanomaterials with circularly polarized luminescence (CPL), which provide new strategies in 3D displays, optical data storage and biosensors. 117 In particular, porphyrin–polypeptide derivatives have been extensively studied as photosensitizers for photodynamic therapy. Here, we will introduce some typical applications such as simulated photosynthesis, photocatalysis, and biomedical applications.…”