Silver nanoparticle films for metal enhanced luminescence: Toward development of plasmonic radiation detectors for medical applications

Research on new materials and devices for medical applications is of utmost importance. Here, we report on the growth of self-assembled Layer-by-Layer (LbL) silver nanoparticles (AgNP) films that were utilized to enhance the optically stimulated luminescence (OSL) emission, and increase the sensitivity of the radiation detectors. Multilayered chitosan/AgNP films were deposited over glass and aluminum substrates, with a top deposition of crystals with radiation-induced luminescence. Samples were irradiated with X-rays and the OSL intensities were recorded. The OSL intensity increases upon increasing the number of AgNP layers, so the detection sensitivity can be tuned accordingly. There is a remarkable OSL enhancement for films deposited over glass substrates, which is attributed to a plasmonic coupling of the X-ray induced luminescent centers and the plasmons at the nanoparticle film surface. However, AgNP films deposited on aluminum substrates led to insignificant OSL enhancement. Detection sensitivity can be tuned by controlling the number of deposited AgNP layers on the glass substrates, or by controlling the distance between the nanoparticle film and the aluminum substrates. These results indicate the potential application of silver nanoparticles films for development of more sensitive and miniaturized radiation detectors for medical applications.