Recent Advances in Light Energy Conversion with Biomimetic Vesicle Membranes

Abstract

Lipid bilayer membranes are ubiquitous in natural chemical conversions. They enable self-assembly and compartmentalization of reaction partners and it becomes increasingly evident that a thorough fundamental understanding of these concepts is highly desirable for chemical reactions and solar energy conversion with artificial systems. This minireview focusses on selected case studies from recent years, most of which were inspired by either membrane-facilitated light harvesting or respective charge transfer. The main focus is on highly biomimetic liposomes with artificial chromophores, and some cases for polymer-membranes will be made. Furthermore, we categorized these studies into energy transfer and electron transfer, with phospholipid vesicles, and polymer membranes for light-driven reactions.

Computation of Förster Resonance Energy Transfer in Lipid Bilayer Membranes

“…In particular, we embed an N-substituted perylene diimide (PDI-C4) as energy donor alongside a modified Ru­(II)–tris­(bipyridine) (Ru-bpyC9) metal complex that acts as the energy acceptor, in a lipid bilayer membrane comprising dioleoylphosphatidylglycerol (DOPG) and dipalmitoylphosphatidylcholine (DPPC) lipids (see Figure ). The use of lipid bilayers, for instance, the spherical membranes of liposomes, is a promising approach toward mimicking natural photosynthesis, as they allow one to confine redox half-reactions, facilitate charge separation, and avoid cross-reactivity. , This approach has been previously employed by some of us . The selected donor molecule is derived from a well-studied organic chromophore, perylene diimide, while the acceptor is the functionalized ruthenium­(II) tris­(bipyridine) model photosensitizer, one of the most widely employed photosensitizers.…”

“…The use of lipid bilayers, for instance, the spherical membranes of liposomes, is a promising approach toward mimicking natural photosynthesis, as they allow one to confine redox half-reactions, facilitate charge separation, and avoid cross-reactivity. 16 , 17 This approach has been previously employed by some of us. 18 The selected donor molecule is derived from a well-studied organic chromophore, perylene diimide, while the acceptor is the functionalized ruthenium(II) tris(bipyridine) model photosensitizer, one of the most widely employed photosensitizers.…”

Mechanistic Insights into the Charge Transfer Dynamics of Photocatalytic Water Oxidation at the Lipid Bilayer–Water Interface

“…Important efforts have been dedicated to achieving artificial photosynthesis by mimicking natural photosynthesis using supramolecular systems, such as micelles, , liposomes, − polymers, − and metal–organic frameworks. , In liposomes, amphiphilic lipid molecules constituting the bilayer are oriented with their polar head groups toward the inner and outer aqueous solutions, while the hydrophobic chains form a nonpolar region between the two interfaces (see Scheme ). In such systems, the bulk solution, the interface, and the membrane core are characterized by distinct dielectric constants, which offers opportunities to prearrange redox-active sites and modify chemical reaction rates and mechanisms, compared to homogeneous conditions. ,− After pioneering but rare reports in the 1980s, several reports about photocatalytic water oxidation in liposomes have recently appeared.…”

Peptide modification on the interior surface of red blood cell ghosts for construction of catalytic reactors

“…Lipid vesicles, surrounded by a phospholipid bilayer, have attracted attention as candidates for development of carriers for drug delivery systems (DDSs) and microreactors for controlling catalytic reactions. [1][2][3][4][5][6][7][8] Membrane surface functionalization of lipid vesicles is important for the surface attachment of targeting ligands toward active DDSs and the organization of catalysts for improving the reactivity. [9][10][11] Commonly used methods for the functionalization are (i) direct exterior surface modification of preformed vesicles using conjugation chemistries such as the reaction of NHS esters with amine, and (ii) selfassembly of lipids containing pre-synthesized amphiphilic functional molecules into vesicles.…”