Simultaneous realization of persistent luminescence and CT dual-mode imaging by x-ray recharged Bi2Ga4O9:Cr nanoprobes in depth-independent tumors

Abstract

Synthesis of excellent imaging nanoparticles plays a critical role in disease detection. Here, novel Bi2Ga4O9:Cr (BGOC) nanoparticles were synthesized for persistent luminescence and computed tomography dual-mode imaging. The Cr3+ ions in the BGOC luminescent nanoparticles were coped as the luminescent center, and the afterglow emission was located in the first biological imaging window. Bi3+ ions served as the computed tomography (CT) imaging contrast agent. The NH2 groups were modified on the surface of the nanoparticles to make them highly biocompatible, and folic acid molecules were modified to facilitate the specificity. This modification facilitated simultaneous persistent luminescence and CT imaging in tumor-bearing mice due to the overexpression of the folic acid molecules’ receptors. Furthermore, instead of visible light, x-rays were used as the excitation light source to activate the BGOC-folic acid nanoprobes and realize long time and high sensitivity imaging of tumors in vivo because of their capacity for deep tissue penetration. Therefore, such nanoprobes can provide a promising depth-independent detection mode for high sensitivity diagnosis and long-term monitoring of diseases.