Gd-DTPA-coupled Ag2Se quantum dots for dual-modality magnetic resonance imaging and fluorescence imaging in the second near-infrared window

Abstract

Near-infrared (NIR) fluorescent quantum dots (QDs) are ideal platforms to fabricate multifunctional contrast agents for multimodal imaging. Herein, second near-infrared window fluorescent (NIR-II) Ag₂Se QDs were coupled with gadopentetate dimeglumine injection (Gd-DTPA) for dual-modality T₁-weighted magnetic resonance (MR) imaging and fluorescence imaging. In vitro experiments suggested that the prepared Ag₂Se-Gd QDs exhibit low cytotoxicity, remarkable T₁-weighted MR imaging, and fluorescence imaging contrast properties. In vivo experiment results showed that Ag₂Se-Gd QDs were the preferred contrast agents for dual-modality T₁-weighted MR imaging and fluorescence imaging with high spatial resolution. Moreover, excellent temporal resolution and high tissue penetration depth were also achieved by fluorescence imaging. These results indicate the potential of Ag₂Se-Gd QDs as multifunctional contrast agents for multimodal imaging in clinical diagnosis and research.