Renal clearable Hafnium-doped carbon dots for CT/Fluorescence imaging of orthotopic liver cancer

Carbon dots (CDs) are emerging as powerful nanoprobes for multiple-model bioimaging. Nowadays, orthotopic xenograft models attract increasing attention because of their superiorities of duplicating the tumor microenvironment. However, compared with the extensive study of subcutaneous xenograft tumors, less attention has been paid to CDs for in vivo orthotopic tumor imaging. Furthermore, it is very desirable for a nanoprobe to achieve preferential accumulation at the tumor site and efficient renal clearance. In this work, a novel kind of Hafnium-doped CDs (HfCDs) were successfully prepared via a simple one-pot pyrolysis method. The significant advantages including robust stability, good biocompatibility, excellent water solubility, remarkable computed tomography (CT) contrast performance and preferential tumor accumulation capability endow HfCDs with particular functions of CT/fluorescence imaging of orthotopic liver cancer initially. More importantly, HfCDs could locate at the tumor site and achieve the rapid imaging within 1 min. The findings of the current study represent a facile and universal approach to fabricate outstanding renal clearable multimodal imaging nanoprobes with great potential for clinical diagnosis.