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CD39 is one of the important nucleotidases to adjust extracellular adenosine triphosphate (ATP) and adenosine diphosphate (ADP) concentration. However, the enzyme mimics to simulate the activity of CD39 still remains to be explored. Herein nitrogen-rich molybdenum nitride (Mo₅N₆) nanosheets are explored to possess CD39-like activity, which are able to catalyze the hydrolysis of the high-energy phosphate bonds (HEPBs) in ATP and ADP but not the common phosphate bonds in adenosine monophosphate (AMP). The catalytic hydrolysis of the phosphate bond over Mo₅N₆-700 nanosheets is first investigated using para-nitrophenyl phosphate as the model substrate and then the CD39-like activity is further explored and verified by ³¹p NMR spectroscopy. Mo⁴⁺ on the surface of Mo₅N₆-700 nanosheets are the catalytic active sites. Using ATP as the model substrate, the K_m and V_max values of CD39-like activity at optimal pH 9.0 are 3.2 µmol L^-1 and 18.5 µmol L^-1 h^-1, respectively. The CD39-like activity of Mo₅N₆-700 nanosheets enabled the down-regulation of intracellular ATP concentration to a larger degree for cancer cells than normal cells, which makes Mo₅N₆-700 nanosheets a potential therapeutic reagent for cancers.

Li-Ion Batteries

In article number 2404456, Jongkook Hwang, Ju Min Kim, and co-workers investigate the effects of different graphite morphologies, analyzed utilizing the cross-slot microfluidic device, on anode slurry rheology, electrode microstructure, and electrochemical performance of Li-ion batteries. The current results show that blending two different graphite morphologies improves the slurry rheological properties while maintaining the electrochemical performance of Li-ion batteries.

Capacitive Deionization

In article number 2403518, Jiansheng Li, Jiayin Yuan, Miao Zhang, and co-workers develop a holey MXene/reduced graphene oxide heterogeneous film by H₂O₂ etching and the subsequent 2D/2D colloidal assembly. The maximized vertical ion channels and optimal interlayer spacing of the film accelerate the charge transfer and ion transport, resulting in enhanced electrosorption performance.

Immunotherapy involving PDL1 degradation holds great potential in anti-tumor treatment. Optimal design of PDL1 degraders and subsequent efficient delivery into tumors are essential for expected efficacy, especially when abnormal tumor vasculature is considered. Herein, a nanodroplet-based novel drug delivery platform termed as NDs^mTx (nanodroplet-based therapeutics) for ultrasound targeted delivery of PDL1 degrader is designed. Briefly, the shell of the NDs^mTx is armed with RGD and mPD1 (a bioorthogonal PD1 mutant produced by genetic codon expansion technology can covalently bind PDL1), and the core is composed of perfluorohexane (PFH, C6F14). The RGD on the NDs^mTx recognizes αvβ3 expressed by tumor vasculature, making NDs^mTx accumulated in tumor practical and visible by low-frequency ultrasound (LFUS). In turn, inertial cavitation induced by LFUS facilitates mPD1 on the nanodroplet debris penetrating the tumor, where mPD1 covalently binds PDL1 and initiates a lysosomal degradation process. Through both in vitro and in vivo study, the superior performance of NDs^mTx in degrading PDL1 and boosting anti-tumor immunity is confirmed. In conclusion, NDs^mTx emerge as an alternative to existing PDL1 blockers in tumor immunotherapy.

Li-Metal Batteries

Surface-functionalized silica mesoball fillers in a composite polymer electrolyte (MSBM-CPE) exhibits greatly increased ionic conductivity and compatibility with the Li anode, resulting in consistent performance and high retention capacity. The molecular dynamics simulations proved the mechanism of synergistically improved Li-ion diffusion. More in article number 2402001, Sang Uck Lee, Jae Hyun Kim, and co-workers.

Solid-State Lighting

In response to the need for efficient, color-rich light-emitting diodes (LEDs), in article number 2311671, Abhishek K. Srivastava and co-workers present tailored nanorods (NRs) enhancing color rendering and luminous efficacy. These double-shelled NRs enable independent color rendering index tuning and achieve up to 99% quantum yield, resulting in efficient LEDs with LE_ele of 214 lm W⁻¹. With their stability, these NR LEDs have the potential to revolutionize lighting technology.

Neuromorphic Computing

In article number 2403737, Jong Kyu Kim and co-workers present a two-dimensional hexagonal boron nitride based memristor with a metal-insulator-semiconductor configuration, specifically designed for energy-efficient neuromorphic applications operating at attojoule levels. This breakthrough has the potential to revolutionize energy usage in neuromorphic systems, bridging the gap in energy efficiency between artificial and biological synapses.

Demand for real-time detection of hydrogen and ammonia, clean energy carriers, in a sensitive and selective manner, is growing rapidly for energy, industrial, and medical applications. Nevertheless, their selective detection still remains a challenge and requires the utilization of diverse sensors, hampering the miniaturization of sensor modules. Herein, a practical approach via material design and facile temperature modulation for dual selectivity is proposed. A Pd nanoparticles-decorated W₁₈O₄₉ nanowire gas sensor is prepared for dual detection of hydrogen and ammonia. The sensor exhibits distinct operating temperatures for ultraselective detection of hydrogen (125 °C) and ammonia (225 °C), with high responses of 35.3 and 133.8, respectively. This dual selectivity with high sensitivity is attributed to enhanced oxygen adsorption, the chemical affinity of sensing materials for target gases, and distinct reactivity profiles of gases. The proposed sensor is further integrated into a microelectromechanical system, enabling its small size, low power consumption, and rapid temperature modulation. Moreover, the practical feasibility of this sensor platform for smart energy monitoring systems is demonstrated by assessing its sensing properties in electrochemical ammonia oxidation reaction systems. This work can provide a practical approach for developing a single gas sensor with multiple functionalities for application in electronic nose systems.

Due to the severe recombination of charge carriers, the photocatalytic activity of covalent organic frameworks (COFs) materials is limited. Herein, through simple ultrasound and stirring processes, the Pd metallene (Pde) is successfully combined with 2D COFs to form Pde/TpPa-1-COF (Pde/TPC) composites. Obviously, a strong internal electric field (IEF) is successfully formed in Pde/TPC hybrid materials, which significantly boosts the separation of photogenerated charges. In addition, the matched 2D structure of the two materials can also lead to electronic coupling effects, plentiful active sites, and shortened carrier migration paths. Thus, the Pde/TPC hybrid materials own extraordinary carrier separation ability with a longer carriers lifetime (3.3 ns for Pde/TPC and 2.7 ns for TPC), which can be proved series of photoelectrochemical and spectroscopic tests. Benefiting from the formation of IEF and the matched 2D structure, the 8% Pde/TPC demonstrates the highest photocatalytic H₂ evolution efficiency, with H₂ production rate reaching up to 5.85 mmol g^-1 h^-1, which is over 25 times greater than that of pristine COFs, also exceeding that of many reported COFs-based photocatalysts. This research provides new perspectives and innovative approaches to further research on enhancing the internal electric field of COFs to promote their photocatalytic performance.