The synthesis of fully conjugated sp 2 -carbon covalent organic frameworks (COF) is extremely challenging given the difficulty of the formation of very stable carbon-carbon double bonds (-C=C-). Here,w er eport the successful preparation of a2 DC OF (TP-COF) based on triazine as central planar units bridged by sp 2 -carbon linkers through the -C = Ccondensation reaction. High-resolution-transmission electron microscopy( HRTEM) clearly confirmed the tessellated hexagonal pore structure with ap ore center-to-center distance of 2nm. Powder X-rayd iffraction (PXRD) together with structural simulations revealed an AA stacking mode of the obtained layered structure.T P-COF turned out to be an excellent semiconductor material with aL UMO energy of À3.23 eV and aband gap of 2.36 eV.Excitingly,this novel sp 2carbon conjugated TP-COF exhibited unprecedented coenzyme regeneration efficiency and can significantly boost the coenzyme-assisted synthesis of l-glutamate to arecord-breaking 97 %yield within 12 minutes.Long-range p-conjugated two-dimensional (2D) materials have received considerable attention in recent years and present ar ange of unique advantages over traditional polymeric materials. [1][2][3][4][5][6][7] In particular, the topological arrangement of aromatic units propagating in two spatial directions equips them with superior (photo-)electronic and magnetic properties. [8][9][10] However,t he delicate control over specific arrangements of functional units to obtain highly ordered 2D materials is still ag reat challenge. [11][12][13][14] Covalent organic frameworks (COFs) take advantage of the structural selfhealing properties stemming from dynamic covalent bond formation. [15][16][17][18][19][20][21] This advancement has made it possible to synthesize well-defined 2D structures with diverse functionalities.A mong all synthetic strategies of COFs,t he most frequently used dynamic covalent-bond-formations trategies are the Schiff base condensation reaction and the boronate ester bond formation. Despite the fact that the extended pconjugation can propagate through the -N = C-double bonds in the Schiff base structure,t he imine-linkage displays relatively poor stability and weak electron delocalization. To overcome this limitation, researchers have been actively exploring new reactions to construct fully conjugated COFs with an optimal electron delocalization. [22][23][24][25][26][27][28] However,examples of fully conjugated imine-free COFs with sp 2 -carbon double bond structures are still rare because it is extremely difficult to form -C = C-bonds via reversible coupling reactions and simultaneously gain the desired conjugation as well as the refined crystallinity within the COF structure.Recently, Jiang et al. and Feng et al. successfully constructed conjugated 2D COFs bearing -C = C-linkage by using Knoevenagel polycondensation. [29][30][31][32] Ther eported sp 2 -carbon linked 2D COFs were demonstrated to have excellent electrochemical and charge-transfer properties.Thee nhanced electron delocalization of sp 2...

Exosomes, a nano-sized subtype of extracellular vesicles secreted from almost all living cells, are capable of transferring cell-specific constituents of the source cell to the recipient cell. Cumulative evidence has revealed exosomes play an irreplaceable role in prognostic, diagnostic, and even therapeutic aspects. A method that can efficiently provide intact and pure exosomes samples is the first step to both exosome-based liquid biopsies and therapeutics. Unfortunately, common exosomal separation techniques suffer from operation complexity, time consumption, large sample volumes and low purity, posing significant challenges for exosomal downstream analysis. Efficient, simple, and affordable methods to isolate exosomes are crucial to carrying out relevant researches. In the last decade, emerging technologies, especially microfluidic chips, have proposed superior strategies for exosome isolation and exhibited fascinating performances. While many excellent reviews have overviewed various methods, a compressive review including updated/improved methods for exosomal isolation is indispensable. Herein, we first overview exosomal properties, biogenesis, contents, and functions. Then, we briefly outline the conventional technologies and discuss the challenges of clinical applications of these technologies. Finally, we review emerging exosomal isolation strategies and large-scale GMP production of engineered exosomes to open up future perspectives of next-generation Exo-devices for cancer diagnosis and treatment.

Food production in green crops is severely limited by low activity and poor specificity of D-ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) in natural photosynthesis (NPS). This work presents a scientific solution to overcome this problem by immobilizing RuBisCO into a microfluidic reactor, which demonstrates a continuous production of glucose precursor at 13.8 μmol g −1 RuBisCO min −1 from CO 2 and ribulose-1,5-bisphosphate. Experiments show that the RuBisCO immobilization significantly enhances enzyme stabilities (7.2 folds in storage stability, 6.7 folds in thermal stability), and also improves the reusability (90.4% activity retained after 5 cycles of reuse and 78.5% after 10 cycles). This work mimics the NPS pathway with scalable microreactors for continuous synthesis of glucose precursor using very small amount of RuBisCO. Although still far from industrial production, this work demonstrates artificial synthesis of basic food materials by replicating the light-independent reactions of NPS, which may hold the key to food crisis relief and future space colonization.

Two-dimensional (2D) N-graphdiyne (N-GDY) nanosheets containing different number of N were synthesized by polymerization of triazine, pyrazine, and pyridine-based monomers at liquid/liquid interface. The configurations and nanostructures of N-GDY were well-characterized. The wettability changed to more hydrophilic as the N contents increased. The collected N-GDY was further employed as metal-free photocatalyst for NADH regeneration. The catalytic performance was related with the N content in the graphdiyne. The N3-GDY demonstrated the best activity. This strategy provided a new promising platform of designing unique 2D N-GDY with tunable performance in biorelated catalysis.

We presented an integrated microfluidic system for dynamical study of cell-microenvironmental interactions. We demonstrated its precisely spatio-temporal control in the flow direction and the multi-site staying of the fluids by groups of monolithic microfabricated valves through digital operation, aside from the regulated communication between two loci based on real-time microenvironment transition. Using this system, a series of functional manipulations, including specific delivery, addressable surface treatment, positional cell loading and co-culture were performed quickly and efficiently for biological applications. Sequentially, we carried out the potential utility of this system in the research of dynamic microenvironmental influence to cells using a patho-physiological interaction during cancer initiation and progression. Our results exhibit the passive role but collaborative response of NIH 3T3 fibroblasts to the soluble signals from hepatocellular carcinoma cells, and also the variable behaviors of carcinoma cells under different environmental stimulation. This system can facilitate the in vitro investigation of cell-microenvironmental interactions occurred in numerous biological and pathogenic processes.

A high-performance self-powered photodetector based on a MoS2/GaAs heterojunction was demonstrated, which demonstrated a high responsivity, specific detectivity, fast response speeds, as well as high polarization sensitivity.

High-performance room-temperature infrared photodetectors based on MoS2/CdTe p–n heterojunction with broadband response, high responsivity, specific detectivity as well as fast response speed were demonstrated.

A self-driven photodetector based on WS2/GaAs type-II Zener heterojunction is fabricated, which shows a broadband response spectrum from 200 to 1550 nm beyond the limitation of the bandgaps with a high responsivity and specific detectivity.