Novel Scintillator-Integrated Highly Sensitive Photonic Films for X-ray Detection via BaF2 Energy Conversion

Ionizing radiation dosimetry is critical in medical and industrial applications, yet conventional dosimeters often lack visual readability and sufficient detection sensitivity. Current radiochromic photonic materials offer wavelength-based dose visualization but face complex fabrication. Here, we develop a novel X-ray-responsive photonic film by magnetically assembling the carbon-encapsulated Fe3O4 (Fe3O4@C) nanochains in a GelMA precursor encapsulated by BaF2 plates. The BaF2 scintillator converts X-rays to UV light, inducing GelMA cross-linking and volumetric contraction, which modulates structural color changes of photonic films. Finite element simulation analysis confirms that radiochromic behaviors stem from a reduction in interparticle spacing of Fe3O4@C nanoparticles (Fe3O4@C NPs) along the nanochains direction. The optimized film (B0.5/Fe4/1L/S-1) achieve a low detection threshold (6 Gy), high sensitivity (4.62 Gy), and linear dose–response (R2 = 0.981, 0–10 Gy). This study integrates scintillator energy conversion with photonic structural color changes, enabling real-time, naked-eye X-ray dosimetry with potential applications in low-dose monitoring.