Mechanistic Process Understanding of the Biomimetic Construction of Porphyrin-Based Light-Capturing Antennas from Self-Assembled Fmoc-Blocked Peptide Templates

Abstract

Natural photosynthesis provides a perfect example of solar energy utilization that converts CO2 to carbohydrates at high efficiency. Herein, an innovative approach was developed to construct light-harvesting antennas via the precise control of porphyrin aggregation and platinum organization on the surface of the self-assembled structures of Fmoc-blocked peptides (Fmoc-ChaChaGK-NH2 and Fmoc-FFGK-NH2). The photophysical properties and the photocatalytic activity of the antenna are dependent on the aggregating structure of porphyrin and arrangement of Pt nanoparticles, which are related closely to the molecular structure of peptides, as well as to the peptide/porphyrin molar ratio and their concentrations. The Fmoc-ChaChaGK/porphyrin complexes prepared at a peptide (Fmoc-ChaChaGK)/TPPS molar ratio of 2 and TPPS concentration of 500 μM possess the highest photo-to-electric conversion efficiency and photocatalytic ability in transforming light energy into chemical energy and storing in the energy-storage molecules (reduced nicotinamide adenine dinucleotide, NADH). The results demonstrate the correlation between the hierarchical structure and light-responsive properties of the antenna and highlight the mediating effect of noncovalent interactions in the construction and stabilization of the photoresponsive materials.

In Situ Probe Supramolecular Self-Assembly Dynamics and Chirality Transfer Mechanism at Air–Water Interface

“…In this work, we used second harmonic generation (SHG) and sum-frequency generation (SFG) technologies to study the supramolecular self-assembly dynamics and chirality transfer of TPPS molecules at l -/ d -G12 amphiphilic monolayers (Figure ). TPPS, a porphyrin derivative often used as a typical photosensitive agent, constructs light-collecting antennas and chiral supramolecular functional materials by precisely controlling the aggregation of porphyrins. − Although TPPS is an achiral molecule, it can self-assemble with intrinsic chiral molecules (such as amino acid molecules) through a variety of synergies of molecular interaction to form self-assembly with supramolecular chirality . We found that TPPS molecules in a saddle-shaped conformation adsorbed onto an amphiphilic cationic monolayer by electrostatic forces and then formed chiral supramolecular assemblies (Figure , right).…”

Peptide‐assistedsupramolecular polymerization of the anionic porphyrinmeso‐tetra(4‐sulfonatophenyl)porphine

“…[54] All of the successful peptide scaffolds discussed, with the exception of di-lysine, also contain hydrophobic amino acids. [26,27,36,[53][54][55][56][57][58] Taken together, it appears there is a balance of cationic charge, hydrophobicity, and aromatic groups that combine to provide a suitable platform for J-aggregate assembly and formation of larger meso-scale aggregates. Importantly, while not evident in our current system, TPPS 4 peptide complexes have been shown to form H-aggregates under certain conditions and would also potentially impact future designs.…”

“…[26,30,31,35,37,49,51,52] Short cationic peptides have been demonstrated to act as scaffolds to facilitate TPPS 4 assembly. [26,[27][28][29]36,53,[53][54][55][56][57][58] Supramolecular nanowires made from J-aggregates of TPPS 4 have potential as building blocks of self-assembling photomaterials if more robust assembly could be achieved under a wider range of conditions.…”

Peptide-Tetrapyrrole Supramolecular Self-Assemblies: State of the Art

“…Xiu et al compared the co-assembly of tetrakis(4-sulfonatophenyl)porphyrin and Pt particles with similar peptides ( 51a – d ) to understand how the peptide molecular structure influences the light harvesting system [ 110 , 111 ]. The Fmoc group and the Cha residue ( 51a ) promoted the assembling and the formation of J-aggregates, enhancing the photo-to-electric conversion efficiency and photocatalytic ability (NAD+/NADH conversion) of these architectures.…”

“…In tetrahydrofuran/water, vesicles with variable size and distribution depending on the molar ratio of the two components are formed, while the addition of trifluoroethanol promotes the transition from supramolecular vesicles to the fiber morphology. -d) to understand how the peptide molecular structure influences the light harvesting system [110,111]. The Fmoc group and the Cha residue (51a) promoted the assembling and the formation of J-aggregates, enhancing the phototo-electric conversion efficiency and photocatalytic ability (NAD+/NADH conversion) of these architectures.…”