Neodymium (3+)‐Coordinated Black Phosphorus Quantum Dots with Retrievable NIR/X‐Ray Optoelectronic Switching Effect for Anti‐Glioblastoma

Heteroatom interaction of atomically thin nanomaterials enables the improvement of electronic transfer, band structure, and optical properties. Black phosphorus quantum dots (BP QDs) are considered to be candidate diagnostic and/or therapeutic agents due to their innate biocompatibility and exceptional photochemical effects. However, BP QDs are not competitive regarding second near-infrared (NIR-II) window medical diagnosis and X-ray induced phototherapy. Here, an Nd3+ ion coordinated BP QD (BPNd) is synthesized with the aim to sufficiently improve its performances in NIR-II fluorescence imaging and X-ray induced photodynamic therapy, benefitting from the retrievable NIR/X-ray optoelectronic switching effects between BP QD and Nd3+ ion. Given its ultrasmall size and efficient cargo loading capacity, BPNd can easily cross the blood-brain barrier to precisely monitor the growth of glioblastoma through intracranial NIR-II fluorescence imaging and impede its progression by specific X-ray induced, synergistic photodynamic chemotherapy.