The catalytic activities of currently developed peroxidase-mimic nanozymes are generally limited. Therefore, further efforts are still needed to improve the catalytic performance of peroxidase nanozymes. Herein, we synthesized Fe-coordinated carbon nanozyme dots (Fe-CDs) that can serve as both efficient peroxidase nanozymes and T 2 -magnetic resonance imaging (MRI) contrast agents. The intrinsic peroxidase-like activity of the Fe-CDs was explored by catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) with hydrogen peroxide (H 2 O 2 ). The product showed better performance over natural horseradish peroxidase (HRP) and other mimetic peroxidases. Quantification of glucose and ascorbic acid detection showed that this nanozyme could be used to detect a minimum limit as low as 5 μM glucose. Moreover, the colorimetric detection technique was used to detect serum glucose in mice, and the detection result was comparable with autobiochemistry analyzer results using a glucose assay kit. Furthermore, the Fe-CDs showed good magnetism properties and provided promising MR imaging of tumors with excellent biocompatibility.

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Periodontitis, one of the most common dental diseases, is the main cause of tooth loss. Bacterial infection and the host immune response are the dominant factors that determine periodontal disease. Therefore, the key factors in the treatment of periodontitis are to remove pathogenic factors and repair periodontal supporting tissues. In this work, a facile and versatile strategy to prepare pH-sensitive biomineralized nanoparticles constructed with antibiotic to simultaneously deliver antibacterial, anti-inflammatory, and bone repair capabilities is presented. The experiments in vitro show that the nanoreactor achieves good inhibitory effects on three common periodontal pathogens and has activity against damaging inflammatory mediators, reducing lipopolysaccharide-induced inflammatory responses. In vivo CT images of the maxillary molar area and histomorphological and immunohistochemical analyses demonstrate that the nanoparticles repair function for periodontal supporting tissues, reverse the loosened alveolar bone tissue, and remodel the periodontal inflammatory microenvironment. Therefore, the present research provides a feasible approach to both prevent the loss of alveolar bone and repair periodontal tissue.