In Vivo Plain X-Ray Imaging of Cancer Using Perovskite Quantum Dot Scintillators

Real-time in vivo detection of cancer via attenuation-based plain X-ray imaging is proposed to fundamentally overcome the penetration depth limits of current fluorescence-based imaging techniques. Using cesium lead bromide (CsPbBr₃, CPB) quantum dot (QD) scintillators, real-time X-ray detection of 5 mm-sized Panc-1 cell tumors grown in a mouse is successfully performed. The QDs are rapidly co-synthesized and double-encapsulated with silicon dioxide (SiO₂) to completely prevent them from being aggregated, decomposed, or released; they are then conjugated with antibodies to target pancreatic cancer. Due to the dramatic X-ray attenuation, the X-ray signal from the CPB QDs placed under the 2 cm-thick tissue is clearly observed, while their fluorescence signal is not detected at all. In in vivo mouse experiments, the injection of a tiny amount (2.8 μg on a QD basis) of the CPB–SiO₂@SiO₂–Ab nanoparticles gives rise to a bright spot at the location of the tumor. Cell viability assay and histological analysis confirm the biocompatibility and nontoxicity of the nanoparticles.