Photosensitized H2 Evolution and NADPH Formation by Photosensitizer/Carbon Nitride Hybrid Nanoparticles

Aptamer-Modified Homogeneous Catalysts, Heterogenous Nanoparticle Catalysts, and Photocatalysts: Functional "Nucleoapzymes", "Aptananozymes", and "Photoaptazymes"

Conjugation of aptamers to homogeneous catalysts ("nucleoapzymes"), heterogeneous nanoparticle catalysts ("aptananozymes"), and photocatalysts ("photoaptazymes") yields superior catalytic/photocatalytic hybrid nanostructures emulating functions of native enzymes and photosystems. The concentration of the substrate in proximity to the catalytic sites ("molarity effect") or spatial concentration of electron-acceptor units in spatial proximity to the photosensitizers, by aptamer-ligand complexes, leads to enhanced catalytic/photocatalytic efficacies of the hybrid nanostructures. This is exemplified by sets of "nucleoapzymes" composed of aptamers conjugated to the hemin/G-quadruplex DNAzymes or metal-ligand complexes as catalysts, catalyzing the oxidation of dopamine to aminochrome, oxygen-insertion into the Ar─H moiety of tyrosinamide and the subsequent oxidation of the catechol product into aminochrome, or the hydrolysis of esters or ATP. Also, aptananozymes consisting of aptamers conjugated to Cu2+ - or Ce4+ -ion-modified C-dots or polyadenine-stabilized Au nanoparticles acting as catalysts oxidizing dopamine or operating bioreactor biocatalytic cascades, are demonstrated. In addition, aptamers conjugated to the Ru(II)-tris-bipyridine photosensitizer or the Zn(II) protoporphyrin IX photosensitizer provide supramolecular photoaptazyme assemblies emulating native photosynthetic reaction centers. Effective photoinduced electron transfer followed by the catalyzed synthesis of NADPH or the evolution of H2 is demonstrated by the photosystems. Structure-function relationships dictate the catalytic and photocatalytic efficacies of the systems.

Functions of metal-phenolic networks and polyphenol derivatives in photo(electro)catalysis

Phenolic compounds are ubiquitous in nature because of their unique physical and chemical properties and wide applications, which have received extensive research attention. Phenolic compounds represented by tannic acid (TA) play an important role at the nanoscale. TA with a polyphenol hydroxyl structure can chemically react with organic or inorganic materials, among which metal-phenolic networks (MPNs) formed by coordination with metal ions and polyphenol derivatives formed by interactions with organic matter, exhibit specific properties and functions, and play key roles in photo(electro)catalysis. In this paper, we first introduce the fundamental properties of TA, then summarize the factors influencing the properties of MPNs and structural transformation of polyphenol-derived materials. Subsequently, the functions of MPNs and polyphenol derivatives in photo(electro)catalysis reactions are summarized, encompassing improving interfacial charge carrier separation, accelerating surface reaction kinetics, and enhancing light absorption. Finally, this article provides a comprehensive overview of the challenges and outlook associated with MPNs. Additionally, it presents novel insights into their stability, mechanistic analysis, synthesis, and applications in photo(electro)catalysis.

Photozyme-Catalyzed ATP Generation Based on ATP Synthase-Reconstituted Nanoarchitectonics

We demonstrate that ATP synthase-reconstituted proteoliposome coatings on the surface of microcapsules can realize photozyme-catalyzed oxidative phosphorylation. The microcapsules were assembled through layer-by-layer deposition of semiconducting graphitic carbon nitride (g-C3N4) nanosheets and polyelectrolytes. It is found that electrons from polyelectrolytes are transferred to g-C3N4 nanosheets, which enhances the separation of photogenerated electron-hole pairs. Thus, the encapsulated g-C3N4 nanosheets as the photozyme accelerate oxidation of glucose into gluconic acid to yield protons under light illumination. The outward transmembrane proton gradient is established to drive ATP synthase to synthesize adenosine triphosphate. With such an assembled system, light-driven oxidative phosphorylation is achieved. This indicates that an assembled photozyme can be used for oxidative phosphorylation, which creates an unusual way for chemical-to-biological energy conversion. Compared to conventional oxidative phosphorylation systems, such an artificial design enables higher energy conversion efficiency.

Efficient Photoinduced Electron Transfer from Pyrene-o-Carborane Heterojunction to Selenoviologen for Enhanced Photocatalytic Hydrogen Evolution and Reduction of Alkynes

A series of pyrene or pyrene-o-carborane-appendant selenoviologens (Py-SeV²⁺ , Py-Cb-SeV²⁺ ) for enhanced photocatalytic hydrogen evolution reaction (HER) and reduction of alkynes is reported. The efficient photoinduced electron transfer (PET) from electron-rich pyrene-o-carborane heterojunction (Py-Cb) with intramolecular charge transfer (ICT) characteristic to electron-deficient selenoviologen (SeV²⁺ ) (k_ET = 1.2 × 10¹⁰ s^-1 ) endows the accelerating the generation of selenoviologen radical cation (SeV^+• ) compared with Py-SeV²⁺ and other derivatives. The electrochromic/electrofluorochromic devices' (ECD and EFCD) measurements and supramolecular assembly/disassembly processes of SeV²⁺ and cucurbit[8]uril (CB[8]) results show that the PET process can be finely tuned by electrochemical and host-guest chemistry methods. By combination with Pt-NPs catalyst, the Py-Cb-SeV²⁺ -based system shows high-efficiency visible-light-driven HER and highly selective phenylacetylene reduction due to the efficient PET process.

Size-Selective Sub-micrometer-Particle Confinement Utilizing Ionic Entropy-Directed Trapping in Inscribed Nanovoid Patterns

We have developed a single-step, high-throughput methodology to selectively confine sub-micrometer particles of a specific size into sequentially inscribed nanovoid patterns by utilizing electrostatic and entropic particle-void interactions in an ionic solution. The nanovoid patterns can be rendered positively charged by coating with an aluminum oxide layer, which can then localize negatively charged particles of a specific size into ordered arrays defined by the nanovoid topography. On the basis of the Poisson-Boltzmann model, the size-selective localization of particles in the voids is directed by the interplay between particle-nanovoid geometry, electrostatic interactions, and ionic entropy change induced by charge regulation in the electrical double layer overlapping region. The underlying principle and developed method could potentially be extended to size-selective trapping, separation, and patterning of many other objects including biological structures.

Cell primitive-based biomimetic functional materials for enhanced cancer therapy

Cell primitive-based functional materials that combine the advantages of natural substances and nanotechnology have emerged as attractive therapeutic agents for cancer therapy. Cell primitives are characterized by distinctive biological functions, such as long-term circulation, tumor specific targeting, immune modulation etc. Moreover, synthetic nanomaterials featuring unique physical/chemical properties have been widely used as effective drug delivery vehicles or anticancer agents to treat cancer. The combination of these two kinds of materials will catalyze the generation of innovative biomaterials with multiple functions, high biocompatibility and negligible immunogenicity for precise cancer therapy. In this review, we summarize the most recent advances in the development of cell primitive-based functional materials for cancer therapy. Different cell primitives, including bacteria, phages, cells, cell membranes, and other bioactive substances are introduced with their unique bioactive functions, and strategies in combining with synthetic materials, especially nanoparticulate systems, for the construction of function-enhanced biomaterials are also summarized. Furthermore, foreseeable challenges and future perspectives are also included for the future research direction in this field.

Hydrothermal synthesis of a CoIn2S4/g-C3N4 heterojunctional photocatalyst with enhanced photocatalytic H2 evolution activity under visible light illumination

CoIn₂S₄, a black semiconducting material, possesses an outstanding visible light response and is employed to modify g-C₃N₄. A series of CoIn₂S₄/g-C₃N₄ heterojunctional photocatalysts are synthesized via a hydrothermal method, whereby cubic CoIn₂S₄ nanosheets are in situ immobilized on the surfaces of porous g-C₃N₄ nanosheets. Compared with the pristine g-C₃N₄ and CoIn₂S₄, under visible light (λ > 420 nm) irradiation, the CoIn₂S₄/g-C₃N₄ composite samples show markedly enhanced photocatalytic activity in hydrogen evolution. Among all of the samples, the 30% CoIn₂S₄/g-C₃N₄ sample shows the maximum H₂ evolution rates, 5.2 and 23.9 times higher than those of g-C₃N₄ and CoIn₂S₄, respectively. The efficient photocatalytic activity of CoIn₂S₄/g-C₃N₄ composite photocatalysts is attributed to the formation of an intimate heterostructure, which not only significantly facilitates charge migration, but also enhances visible light absorption. Moreover, a plausible photocatalytic mechanism for the composite photocatalyst has been elucidated. This research provides a novel hint for fabricating visible-light-responsive heterojunction photocatalysts with high performance for energy production.