Development of an optically stimulated luminescence radiometer based on sodium chloride and gold nanoparticles for improving radiation detection in radiography

Abstract Purpose To evaluate sodium chloride doped with gold nanoparticles (NaCl + GNPs) as a low‐cost, reusable optically stimulated luminescence (OSL) material for diagnostic radiology, and to benchmark its luminescence performance against the commercial standard, aluminum oxide doped with carbon (Al 2 O 3 :C). Methods NaCl + GNPs detectors were fabricated through solution‐based doping, solvent evaporation, pellet pressing, and two‐stage thermal treatment. Structural characterization was verified via UV–Vis spectroscopy. OSL performance was assessed under diagnostic X‐ray energies ranging from 40 to 150 kVp, using Al 2 O 3 :C as the reference. Evaluated parameters included OSL signal linearity, reproducibility, bleaching efficiency, fading behavior, minimum detectable signal (MDS), energy dependence, and mass scaling. Measurements were performed using equal and variable detector masses (20–60 g) across a dose range of approximately 6–60 mGy. Results NaCl + GNPs exhibited strong linearity ( R 2 > 0.99) across the tested exposure range and produced reproducible OSL signals over repeated irradiations. The material demonstrated an energy‐dependent increase in luminescence comparable to Al 2 O 3 :C, with the 40 g NaCl + GNPs sample achieving 96–97% of the Al 2 O 3 :C OSL signal at 150 kVp. Increasing detector mass enhanced luminescence output proportionally, with 60 g samples exceeding the reference material at energies above 100 kVp. Bleaching efficiency was notably high, with consistently minimal residual signal, confirming excellent reusability. The MDS was approximately equivalent to 0.4–0.5 mGy in relative terms. However, NaCl + GNPs showed faster fading, with ∼50% signal loss over 9 h, indicating the importance of timely readout or controlled storage. Conclusions Gold nanoparticle incorporation enhances the luminescent efficiency and usability of NaCl, producing a material that is low‐cost, scalable, and highly effective in bleaching. Although slightly less sensitive than Al 2 O 3 :C, the NaCl + GNPs detectors demonstrate strong performance, favorable reproducibility, and minimal residual signal, making them a practical option for clinical, educational, and resource‐limited dosimetry applications.