Optically Stimulated Luminescence Under Plasmon Resonance Conditions Enhances X-Ray Detection

Plasmon enhancement of luminescence close to noble metal nanoparticles is a powerful tool for many optical purposes. Although the plasmon properties of noble metal nanoparticles found application in many different areas, no reports on their use to detect ionizing radiation exist. Here, we investigate the use of the localized surface plasmon resonance of noble metal nanoparticles, to obtain plasmon-enhanced optically stimulated luminescence (OSL). The OSL intensity depends on particle size: we observed enhanced OSL in samples containing silver nanoparticles and quenched OSL in samples bearing silver microparticles. The local field close to the nanoparticles surface under surface plasmon resonance condition increased the excitation rate of the X-ray-generated F centers, enhancing luminescence. Moreover, noble metal nanoparticles can also concentrate luminescent centers close to their surface, leading to a synergistic effect that facilitates detection and intensify OSL. These promising findings may give rise to a new class of ionizing radiation detectors.