Widespread bacterial resistance induced by the abuse of antibiotics eagerly needs the exploitation of novel antimicrobial agents and strategies. Gold nanoclusters (Au NCs) have recently emerged as an innovative nanomedicine, but study on their antibacterial properties especially toward multidrug resistant (MDR) bacteria is scarce. Herein, we demonstrate that a novel class of Au NCs, mercaptopyrimidine conjugated Au NCs, can act as potent nanoantibiotics targeting these intractable superbugs in vitro and in vivo, without induction of bacterial antibiotic resistance and noticeable cytotoxicity to mammalian cells. The Au NCs kill these superbugs through a combined mechanism including cell membrane destruction, DNA damage, and reactive oxygen species (ROS) generation, and exhibit excellent treatment effects in both macrophages and animal infection models induced by methicillin-resistant Staphylococcus aureus as representative. Moreover, the induction of intracellular ROS production in bacterial cells mainly attributed to the Au NCs' intrinsic oxidase- and peroxidase-like catalytic activities has been demonstrated for the first time.

Functionalized hydrogels have aroused general interest due to their versatile applications in biomaterial fields. This work reports a hydrogel network composed of gold nanoclusters linked with bivalent cations such as Ca2+, Mg2+, and Zn2+. The hydrogel exhibits both aggregation‐induced emission (AIE) and aggregation‐induced electrochemiluminescence (AIECL) effects. Most noteworthy, the AIECL effect (≈50‐fold enhancement) is even more significant than the corresponding AIE effect (approximately fivefold enhancement). Calmodulin, a Ca2+ binding protein, may efficiently regulate the AIECL dynamics after specific binding of the Ca2+ linker, with the linear range from 0.3 to 50 µg mL−1 and a limit of detection of 0.1 µg mL−1. Considering the important roles of bivalent cations in the life system, these results may pave a new avenue for the design of a biomolecule‐responsive AIECL‐type hydrogel with multifunctional biomedical purposes.

Despite all the efforts to develop an ideal technology for cancer treatment, vital parameters, such as reducing the adverse effects and improving treatment efficiency, still require significant improvement. For this purpose, the rational design of a smart stimuli-responsive and fully biodegradable delivery system is of great significance. By using ZIF-8 nanoparticles as a sacrificial template, black phosphorous quantum dots (BPQDs) and S-nitrosoglutathione (GSNO) were successfully encapsulated into HKUST-1@MIL-100. In cancerous cells, the high glutathione (GSH) and reactive oxygen species (ROS) levels trigger the sequential reaction to rebuild the redox equilibrium and stimulate the continuous production of NO and hydroxyl radicals. As a result, the MOFs serve not only as carriers and contrast agents but also as the catalysts for the generation of NO and $OH, which results in maximum atomic efficiency. Finally, the nanosystem completely degrades into small molecules and is excreted from the body.

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