Boric Acid-Derived Carbon Dot Scintillators for X-ray Imaging

Conventional carbon dots (CDs) exhibit negligible radioluminescence (RL) under ambient conditions, precluding their use in X-ray detection. Herein, we overturn this limitation with a metal-free CD scintillator engineered via synergistic matrix rigidification and defect engineering, achieved by compositing methoxyquinoline derivatives with boric acid (BA). The B2O3 rigid matrix derived from BA pyrolysis effectively suppresses molecular vibrations and introduces oxygen-vacancy channels of CDs, endowing photoluminescence quantum yield reaching 43.92% and low detection limit of 107 nGy s–1. The materials retain >90% intensity after 90 cycles at 298 μGy s–1 and can be operated up to 180 °C. Biocompatibility assessments show favorable hemocompatibility and cytocompatibility. In 3D printed vessels and tumor phantoms, the CD-based scintillation film furnishes real-time X-ray visualization of iohexol flow and laser-ablation margins with 0.8 mm spatial resolution, validating its translational potential for low-dose, image-guided interventions. This work provides a metal-free CD scintillator platform for dynamic imaging and real-time radiation detection.