当前临床实践中使用的对比剂和肿瘤治疗方法远不能令人满意，主要是由于肿瘤微环境（TME）的特异性。高对比度和治疗效果强的诊断和治疗试剂的识别仍然是一个巨大的挑战。在本研究中，我们首次使用甲苯胺蓝（TB）和锰作为原料成功合成了一种新型的碳点纳米酶（Mn-CD）。如预期，Mn-CDs 在对 TME（酸度和谷胱甘肽）的响应中实现了增强的磁共振（MR）成像能力，并且 r1 和 r2 松弛率分别增强了 224% 和 249%。此外，Mn-CDs 的光稳定性也得到了改善，并且显示出了 1 O2 高效产率为 1.68。此外，Mn-CDs 还可以表现出高效的过氧化物酶（POD）样活性，并催化过氧化氢生成羟基自由基，在光照条件下改善了活性。体外和体内的结果表明，Mn-CDs 能够通过肿瘤部位的增强渗透和保留效应聚集，实现对 TME 易感性的实时 MR 成像，并促进光增强的化学动力学和光动力学组合治疗。这项研究为碳纳米材料在疾病综合诊断和治疗中的作用开辟了新的视角。© 2023 Wiley-VCH GmbH.

The contrast agents and tumor treatments currently used in clinical practice are far from satisfactory, due to the specificity of the tumor microenvironment (TME). Identification of diagnostic and therapeutic reagents with strong contrast and therapeutic effect remains a great challenge. Herein, a novel carbon dot nanozyme (Mn-CD) is synthesized for the first time using toluidine blue (TB) and manganese as raw materials. As expected, the enhanced magnetic resonance (MR) imaging capability of Mn-CDs is realized in response to the TME (acidity and glutathione), and r1 and r2 relaxation rates are enhanced by 224% and 249%, respectively. In addition, the photostability of Mn-CDs is also improved, and show an efficient singlet oxygen (1 O2 ) yield of 1.68. Moreover, Mn-CDs can also perform high-efficiency peroxidase (POD)-like activity and catalyze hydrogen peroxide to hydroxyl radicals, which is greatly improved under the light condition. The results both in vitro and in vivo demonstrate that the Mn-CDs are able to achieve real-time MR imaging of TME responsiveness through aggregation of the enhanced permeability and retention effect at tumor sites and facilitate light-enhanced chemodynamic and photodynamic combination therapies. This work opens a new perspective in terms of the role of carbon nanomaterials in integrated diagnosis and treatment of diseases.© 2023 Wiley-VCH GmbH.