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Bone tissue is a complex biocomposite material with a variety of organic (e.g., proteins, cells) and inorganic (e.g., hydroxyapatite crystals) components hierarchically organized with nano/microscale precision. Based on the understanding of such hierarchical organization of bone tissue and its unique mechanical properties, efforts are being made to mimic these organic–inorganic hybrid biocomposites. A key factor for the successful designing of complex, hybrid biomaterials is the facilitation and control of adhesion at the interfaces, as many current synthetic biomaterials are inert, lacking interfacial bioactivity. In this regard, researchers have focused on controlling the interface by surface modifications, but the development of a simple, unified way to biofunctionalize diverse organic and inorganic materials remains a critical challenge. Here, a universal biomineralization route, called polydopamine‐assisted hydroxyapatite formation (pHAF), that can be applied to virtually any type and morphology of scaffold materials is demonstrated. Inspired by the adhesion mechanism of mussels, the pHAF method can readily integrate hydroxyapatites on ceramics, noble metals, semiconductors, and synthetic polymers, irrespective of their size and morphology (e.g., porosity and shape). Surface‐anchored catecholamine moieties in polydopamine enriches the interface with calcium ions, facilitating the formation of hydroxyapatite crystals that are aligned to the c‐axes, parallel to the polydopamine layer as observed in natural hydroxyapatites in mineralized tissues. This universal surface biomineralization can be an innovative foundation for future tissue engineering.

Highly photoactive, graphene-wrapped anatase TiO(2) nanoparticles are synthesized through one-step hydrothermal reduction of graphene oxide (GO) and TiO(2) crystallization from GO-wrapped amorphous TiO(2) NPs. Graphene-TiO(2) nanoparticles exhibit a red-shift of the band-edge and a significant reduction of the bandgap (2.80 eV). Graphene-TiO(2) nanoparticles possess excellent photocatalytic properties under visible light for the degradation of methylene blue.

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Biocatalytic transformation has received increasing attention in the green synthesis of chemicals because of the diversity of enzymes, their high catalytic activities and specificities, and mild reaction conditions. The idea of solar energy utilization in chemical synthesis through the combination of photocatalysis and biocatalysis provides an opportunity to make the "green" process greener. Oxidoreductases catalyze redox transformation of substrates by exchanging electrons at the enzyme's active site, often with the aid of electron mediator(s) as a counterpart. Recent progress indicates that photoinduced electron transfer using organic (or inorganic) photosensitizers can activate a wide spectrum of redox enzymes to catalyze fuel-forming reactions (e.g., H evolution, CO reduction) and synthetically useful reductions (e.g., asymmetric reduction, oxygenation, hydroxylation, epoxidation, Baeyer-Villiger oxidation). This Review provides an overview of recent advances in light-driven activation of redox enzymes through direct or indirect transfer of photoinduced electrons.

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The use of biologically occurring redox centres holds a great potential in designing sustainable energy storage systems. Yet, to become practically feasible, it is critical to explore optimization strategies of biological redox compounds, along with in-depth studies regarding their underlying energy storage mechanisms. Here we report a molecular simplification strategy to tailor the redox unit of pteridine derivatives, which are essential components of ubiquitous electron transfer proteins in nature. We first apply pteridine systems of alloxazinic structure in lithium/sodium rechargeable batteries and unveil their reversible tautomerism during energy storage. Through the molecular tailoring, the pteridine electrodes can show outstanding performance, delivering 533 Wh kg À 1 within 1 h and 348 Wh kg À 1 within 1 min, as well as high cyclability retaining 96% of the initial capacity after 500 cycles at 10 A g À 1 . Our strategy combined with experimental and theoretical studies suggests guidance for the rational design of organic redox centres.

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