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

Abstract 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 (CsPbBr 3 , 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 (SiO 2 ) 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–SiO 2 @SiO 2 –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.