Nitrogen-doped reduced graphene oxide/black phosphorus quantum dot composites for electrocatalytic treatment of choroidal melanoma

Choroidal melanoma (CM) is a melanocyte-derived intraocular malignancy that poses a great threat to patients' vision and life. Electrochemical therapy, which relies on the generation of reactive oxygen species via an oxygen reduction reaction (ORR) to kill target cells, has emerged as a promising approach for the local treatment of malignant tumors. In this study, nitrogen-doped reduced graphene oxide (N-rGO) was electrostatically bound with black phosphorus (BP) quantum dots to form a composite system (N-rGO-BP) for tumor therapy. Owing to the synergistic effect of the two components, the optimal catalyst (N-rGO-BP-12) exhibits improved electrochemical properties and stability, achieving a more positive half-wave potential of 0.66 V and a larger steadystate current density of 2.76 mA cm-2 compared with the N-rGO precursor. In electrochemical therapy, NrGO-BP-12 undergoes ORR via a two-electron pathway in the acidic microenvironment of the tumor, producing large amounts of hydrogen peroxide and hydroxyl radical to kill tumor cells; only 25 % of the human CM cells survive after 3 h of the treatment. This study provides a new approach for the synthesis and application of electrochemical catalysts for clinical tumor therapy.