Cu-Doped black phosphorus quantum dots as multifunctional Fenton nanocatalyst for boosting synergistically enhanced H2O2-guided and photothermal chemodynamic cancer therapy

Chemodynamic therapy (CDT) is a cancer treatment that converts endogenous H2O2 into hydroxyl radicals (˙OH) through Fenton reaction to destroy cancer cells. However, there are still some challenges in accelerating the Fenton reaction of CDT and improving the biodegradability of nanocatalysts. Herein, a multifunctional biomimetic BPQDs-Cu@GOD (BCG) Fenton nanocatalyst for boosting synergistically enhanced H2O2-guided and photothermal CDT of cancer is reported. Cu2+ in BCG can be reduced to Cu+ by black phosphorus quantum dots (BPQDs), triggering a Cu+-mediated Fenton-like reaction to degrade H2O2 and generate abundant ˙OH for cancer CDT. The loaded glucose oxidase (GOD) can consume the glucose in the tumor to produce abundant H2O2 for Fenton-like reaction. In addition, Cu2+ in BCG can react with GSH in tumor cells to alleviate the antioxidant capacity of tumor tissues, further improving the CDT efficacy. Furthermore, the photothermal performance of BPQDs can be enhanced by capturing Cu2+, improving the photoacoustic imaging and photothermal therapy (PTT) functions. More importantly, the enhanced photothermal performance can rapidly accelerate the Fenton-like reaction under NIR irradiation. Finally, Cu2+ can accelerate the degradation of BPQDs, which can reduce the retention of reagents. As a novel multifunctional biocompatible Fenton nanocatalyst, BCG have great potential in cancer therapy.