Nanocatalytic therapy, involving the nanozyme-triggered production of reactive oxygen species (ROS) in the tumor microenvironment (TME), has demonstrated potential in tumor therapy, but nanozymes still face challenges of activity and specificity that compromise the therapeutic efficacy. Herein, we report a strategy based on a single-atom nanozyme to initiate cascade enzymatic reactions in the TME for tumorspecific treatment. The cobalt-single-atom nanozyme, with CoÀ N coordination on N-doped porous carbon (Co-SAs@NC), displays catalase-like activity that decomposes cellular endogenous H 2 O 2 to produce O 2 , and subsequent oxidase-like activity that converts O 2 into cytotoxic superoxide radicals to efficiently kill tumor cells. By incorporation with doxorubicin, the therapy achieves a significantly enhanced antitumor effect in vivo. Our findings show that cascade TME-specific catalytic therapy combined with chemotherapy is a promising strategy for efficient tumor therapy.

Single-mode optical rib waveguides operating at telecommunication wavelengths are successfully patterned via a hot embossing technique in a thermally evaporated chalcogenide glass thin film on a chalcogenide glass substrate. Ellipsometry is used to measure the refractive index dispersion of the pressed film (As(40)Se(60)) and substrate (Ge(17)As(18)Se(65)).

To extend the functionalities of two-dimensional graphene-like layered compounds as versatile materials, the modification of transition metal dichalcogenide nanosheets such as MoS2 with metal nanoparticles is of great and widespread interest. However, few studies are available on the preparation of bimetallic nanoparticles supported on MoS2. Herein, a facile and efficient method to synthesize MoS2-PtAg nanohybrids by decorating ultrathin MoS2 nanosheets with octahedral Pt74Ag26 alloy nanoparticles has been reported. The as-prepared MoS2-Pt74Ag26 nanohybrids were investigated as novel peroxidase mimics to catalyze the oxidation of classical peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2, producing a blue colored reaction and exhibiting typical Michaelis-Menten kinetics. MoS2-Pt74Ag26 has a higher affinity for H2O2 than horseradish peroxidase (HRP) and a higher vmax value with TMB as the substrate than MoS2. The improved catalytic activity of hybrids for colorimetric reactions could be attributed to the synergistic effects of octahedral Pt74Ag26 nanoparticles and ultrathin MoS2 nanosheets as supports. Meanwhile, the generation of active oxygen species (˙OH) by H2O2 decomposition with MoS2-Pt74Ag26 was responsible for the oxidation of TMB. On the basis of these findings, a colorimetric method based on MoS2-Pt74Ag26 nanohybrids that is highly sensitive and selective was developed for glucose detection. Lower values of the limit of detection (LOD) were obtained, which is more sensitive than MoS2 nanosheets.

Li‐CO 2 battery has attracted extensive attention and research due to its super high theoretical energy density and its ability to fix greenhouse gas CO 2 . However, the slow reaction kinetics during discharge/charge seriously limits its development. Hence, a simple cation exchange strategy is developed to introduce Ru atoms onto a Co 3 O 4 nanosheet array grown on carbon cloth (SA Ru‐Co 3 O 4 /CC) to prepare a single atom site catalyst (SASC) and successfully used in Li‐CO 2 battery. Li‐CO 2 batteries based on SA Ru‐Co 3 O 4 /CC cathode exhibit enhanced electrochemical performances including low overpotential, ultra high capacity, and long cycle life. Density functional theory calculations reveal that single atom Ru as the driving force center can significantly enhance the intrinsic affinity for key intermediates, thus enhancing the reaction kinetics of CO 2 reduction reaction in Li‐CO 2 batteries, and ultimately optimizing the growth pathway of discharge products. In addition, the Bader charge analysis indicates that Ru atoms as electron‐deficient centers can enhance the catalytic activity of SA Ru‐Co 3 O 4 /CC cathode for the CO 2 evolution reaction. It is believed that this work has important implications for the development of new SASCs and the design of efficient catalyst for Li‐CO 2 batteries.