Ru/Co-N,Zn-doped carbon nanocubes with multiple enzyme-like activities for high-efficiency glucose detection and self-supplying cascaded nanodrug in synergistic cancer therapy

Nanozyme technology is increasingly utilized in biosensing and biomedicine fields. To advancing this technology, it is pivotal for constructing high-quality nanozymes and expanding their multifunctional applications. Herein, Co nanoparticles embedded within N,Zn-doped carbon nanocubes (Co-N,Zn-CNCs) were facilely prepared by pyrolysis, followed by surface modification with Ru nanoparticles (termed Ru/Co-N,Zn-CNCs). The resultant material exhibited peroxidase (POD)-, catalase (CAT)- and glutathione oxidase (GSHOx)-mimic activities. After attachment of glucose oxidase (GOx), a bifunctional self-supply cascaded nanodrug system (Ru/Co-N,Zn-CNCs-GOx) was established. Specifically, the nanozyme based colorimetric sensor was constructed for visually glucose detection, showing a good linear relationship in a range of 10 to 2000 μM and a low detection limit of 0.61 μM. Further, the cascaded nanodrug exhibited high-efficiency for eradicating cancer cells by reactive oxygen species mediated chemodynamic therapy, hypoxia alleviation, and starvation therapy, coupled by realizing ferroptosis of the cancer cells. The versatile cascaded nanozyme shows potential applications in biosensing, cancer therapy, and beyond.