Bismuth- and gadolinium-codoped carbon quantum dots with red/green dual emission for fluorescence/CT/T1-MRI mode imaging

Abstract

Carbon quantum dots (CQDs) with good biosafety can be doped with metals to construct multimodal imaging probes with a wide range of applications in fluorescence and molecular imaging. However, developing CQDs with both long-wavelength emission and a variety of imaging modes remains a challenge. In this article, novel bismuth- and gadolinium-codoped carbon quantum dots (Bi,Gd-CQDs) were developed using a hydrothermal method for green and red fluorescence imaging, X-ray computed tomography (CT) imaging, and T1-weighted magnetic resonance imaging (T1-weighted MRI). In addition to exceptional water solubility, strong steady fluorescence characteristics, and great biocompatibility, the obtained Bi,Gd-CQDs have a high X-ray attenuation coefficient and a short magnetic resonance T1 relaxation time. Additionally, cell imaging involved red fluorescence imaging with deep penetration. Therefore, the prepared Bi,Gd-CQDs with green and red dual-emissions can be used as nanoprobes for fluorescence, CT, and T1-weighted MR imaging, expanding their application prospects in the field of biomedicine.