Complex multiple-component semiconductor photocatalysts can be constructed that display enhanced catalytic efficiency via multiple charge and energy transfer, mimicking photosystems in nature. In contrast, the efficiency of single-component semiconductor photocatalysts is usually limited due to the fast recombination of the photogenerated excitons. Here, we report the design of an asymmetric covalent triazine framework as an efficient organic single-component semiconductor photocatalyst. Four different molecular donor-acceptor domains are obtained within the network, leading to enhanced photogenerated charge separation via an intramolecular energy transfer cascade. The photocatalytic efficiency of the asymmetric covalent triazine framework is superior to that of its symmetric counterparts; this was demonstrated by the visible-light-driven formation of benzophosphole oxides from diphenylphosphine oxide and diphenylacetylene.

The reduction of CO2 with visible light is a highly sustainable method for producing valuable chemicals. The function‐led design of organic conjugated semiconductors with more chemical variety than that of inorganic semiconductors has emerged as a method for achieving carbon photofixation chemistry. Here, we report the molecular engineering of triazine‐based conjugated microporous polymers to capture, activate and reduce CO2 to CO with visible light. The optical band gap of the CMPs is engineered by varying the organic electron‐withdrawing (benzothiadiazole) and electron‐donating units (thiophene) on the skeleton of the triazine rings while creating organic donor–acceptor junctions to promote the charge separation. This engineering also provides control of the texture, surface functionality and redox potentials of CMPs for achieving the light‐induced conversion of CO2 to CO ambient conditions.

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A three-component nanocapsule-based system allows monitoring the health cycle of coatings via autonomous visual highlighting of damages and reversible erasing through healing.

cell's total energy budget. [2] The universal energy currency that is used for these purposes and can be found in all forms of life is adenosine triphosphate (ATP). A vast majority of the cellular energy demand is covered by either converting a large variety of energy-rich substrates into ATP in a process called oxidative phosphorylation, or by converting light (electromagnetic) energy into ATP in a process called photophosphorylation (or photosynthesis).These naturally existing energy conversions are valid in in the context of bottomup synthetic biology as well. In the latter, an artificial cell is envisioned as a compendium of functional modules, each hand-tailored to partially or entirely mimic one of the essential life processes, such as reproduction, growth, motility, etc. [3] Like their natural counterparts, all these reenvisioned synthetic processes are energy demanding, therefore, the deliberate design of synthetic cells should involve suitable energy management strategy, by, for example, continuous regeneration of ATP. Apart from the importance in the context of artificial cells, new energy conversion strategies can be considered as a standalone feature for enzymatic and cell-free biotechnology, wherein bottom-up synthetic biology might also deliver new and sustainable solutions.The notion of synthetic in terms of engineered and/or non-natural can be even expanded to other forms of energy (like electrical energy) and non-natural building blocks. The chemically driven ATP synthesis, as in oxidative phosphorylation, represents a spontaneous process, in which the electrons of a fuel (glucose, NADH) are transferred to an electron acceptor such as oxygen with the concomitant generation of proton gradient, which is afterwards stored again as chemical energy in ATP. In the realm of synthetic biology, other options might also be feasible, for example: can we use electrical energy and directly plug it in to drive biological processes [4,5] or make use of natural electron transfer mechanisms to produce electricity? [6] The Electron Transport Chain-a Natural Toolbox of Functional Parts for the Construction of Artificial OrganellesDuring the process of oxidative phosphorylation, electrons are passed from an electron donor ("fuel") with a more negative One of the critical steps in sustaining life-mimicking processes in synthetic cells is energy, i.e., adenosine triphosphate (ATP) regeneration. Previous studies have shown that the simple addition of ATP or ATP regeneration systems, which do not regenerate ATP directly from ADP and P i , have no or only limited success due to accumulation of ATP hydrolysis products. In general, ATP regeneration can be achieved by converting light or chemical energy into ATP, which may also involve redox transformations of cofactors. The present contribution provides an overview of the existing ATP regeneration strategies and the related nicotinamide adenine dinucleotide (NAD + ) redox cycling, with a focus on compartmentalized systems. Special attention is being paid to those approach...

Bottom‐up synthetic biology is the science of building systems that mimic the structure and function of living cells from scratch. To do this, researchers combine tools from chemistry, materials science, and biochemistry to develop functional and structural building blocks to construct synthetic cell‐like systems. The many strategies and materials that have been developed in recent decades have enabled scientists to engineer synthetic cells and organelles that mimic the essential functions and behaviors of natural cells. Examples include synthetic cells that can synthesize their own ATP using light, maintain metabolic reactions through enzymatic networks, perform gene replication, and even grow and divide. In this Review, we discuss recent developments in the design and construction of synthetic cells and organelles using the bottom‐up approach. Our goal is to present representative synthetic cells of increasing complexity as well as strategies for solving distinct challenges in bottom‐up synthetic biology.

The regeneration of enzymatic cofactors by cell-free synthetic modulesi sak ey step towards producing ap urely synthetic cell. Herein, we demonstrate the regeneration of the enzyme cofactor NAD + by photo-oxidation of NADH under visible-light irradiation by using metal-free conjugated polymer nanoparticles. Encapsulation of the light-activen anoparticles in the lumen of polymeric vesicles produced af ully organic module able to regenerate NAD + in an enzyme-free system.T he polymer compartment conferred physical and chemicala utonomy to the module, allowing the regenerationo fN AD + to occur efficiently,e ven in harshc hemical environments. Moreover,w e show that regeneration of NAD + by the photocatalyst nanoparticles can oxidize am odel substrate, in conjunction with the enzymeg lycerol dehydrogenase. To ensure the longevity of the enzyme, we immobilizedi tw ithin ap rotectives ilica matrix;t his yieldede nzymatic silican anoparticles with enhanced long-term performance and compatibility with the NAD + -regeneration system.The immobilizationo re ncapsulationo ff unctional parts in artificial compartmentsi sapowerful way to create responsive autonomous objects, or functional modules, that displaylocalized input-output properties. [1] Synthetic biology uses artificially designed modules as systems that can reproduce simple cell-like activity and even mimic rudimentary cellular behavior. [2] Some examples include the cell-free synthesis of ATP, [3] cytoskeleton and microtubule reconstitution, [4] self-replication of giant vesicles, [5] and av ariety of compartmentalized biochemical reactions. [6] The cell-free regulation of nicotinamide adenine nucleotide (NAD) coenzymes has been an important target in photocatalysis and functional module design. [7] In cells, NAD coenzymes controlt he flow of electrons in numerous redox transformations involvingo xidoreductases and are key components for the conversion and storageo fe nergy during photosynthesis. Therefore, the ability to control the redox state of NAD in a functional module offers aw ay to simplify and optimize the use of numerous enzymatic redox transformations,m any of them with relevant synthetic applications. [8] Previous work in this area has focused mainly on creating NAD modules containing inorganic photocatalysts, such as TiO 2 and other metal-based nanoparticles, encapsulatedi nt he lumen of lipid vesicles or embedded in solid matrices. [9] To date, most developmentsi nt his area has focusedo nr egenerating NADH through the photocatalytic reduction of NAD + . These metal-based catalysts show high versatility,s electivity, and excellent photocatalytic properties, but they can also suffer from the need for mediators or excitation wavelengths in the UV region, whichc an be harmful to other components in the system.Herein, we report the designo fametal-free, polymer-based NAD module that regenerates NAD + through the nonenzymatic photocatalytic oxidation of NADH by using visiblel ight. Our photocatalyst consisted of conjugated microporous polymer nano...

A structural design of conjugated microporous polymers for the photocatalytic carbon–carbon double bond cleavage is presented.