A novel bi-modal probe based on BaHoF5 and Cu-doped QDs with enhanced CT contrast efficiency and fluorescent brightness for tumor-targeting imaging.

Abstract

In this work, a novel bi-modal imaging probe with enhanced CT contrast efficiency and FL brightness was constructed, in which the combination of a binary CT contrast agent BaHoF5 and Cu-doped QDs served as a vehicle; hyaluronic acid (HA) was employed as a tumor-targeting ligand. With its CT contrast efficiency about 2.1- and 3.9-fold higher than PEG-BaHoF5 and Iohexol, the CT contrast efficiency and the fluorescent brightness of the bi-modal probe were both enhanced. Likewise, its fluorescent brightness is almost 6-fold brighter after Cu-doped QDs loading. The most important contribution of thiswork lies on the proposed strategy. The inherent contradiction of the imaging sensitivity of CT and FL imaging iswell balanced and a great CT/FL bi-modal imaging performance issimultaneously obtained even atlow concentration (400μg/mL) of the probe, which was superior to the previous CT/FL bi-modal probes. Moreover, since BaHoF5 as a binary CT contrast agent was introduced instead of conventional Au and Bi2S3, the CT/FL bi-modal probe would be more suitable for different patients under different operation voltages. In addition, the in vitro tumor cell imaging also demonstrated a good photo-stability, FL brightness, and tumor-targeting capability of the probe, indicating its great potential in practical bi-modal imaging for further tumor diagnosis and therapy. Graphical abstract A novel bi-modal imaging probe with enhanced CT contrast efficiency and FL brightness was fabricated, in which its CT contrast efficiency was about 2.1- and 3.9-fold higher than PEG-BaHoF5 and Iohexol, respectively, and its fluorescent brightness almost 6-fold brighter after Cu-doped QDs loading.