Enhanced X-ray Attenuating Efficiency of Silicon Dioxide Nanoparticles with Cesium Lead Bromide and 2,5-Diphenyloxazole Co-Embedded Therein

Abstract

An X-ray-attenuation-based in vivo imaging can be a promising candidate for real-time detection of cancer in an early stage due to its significantly longer penetration depth compared to currently investigated fluorescence-emission-based imaging techniques. It has recently been demonstrated that this novel concept of imaging is feasible using cesium lead bromide (CPB) quantum dots (QDs) stably embedded in silicon dioxide (SiO2) nanoparticles (NPs). However, further improvements are necessary to realize its practical use, especially in terms of X-ray attenuation efficiency. In this study, we have found that the X-ray attenuation capability of CPB/SiO2 NPs was significantly enhanced by embedding an organic X-ray scintillator, 2,5-diphenyloxazole (PPO), together with CPB QDs in the NPs. The embedment not only solved the water dispersibility and stability problem of PPO, but also significantly increased the Hounsfield unit of the NPs, which was proportional to the degree of X-ray attenuation, by 2.7 times.

Keywords

• X-ray attenuation
• attenuation-based imaging
• cesium lead bromide
• 2,5-diphenyloxazole
• Hounsfield unit