Superparamagnetic graphene quantum dot as a dual‐modality contrast agent for confocal fluorescence microscopy and magnetomotive optical coherence tomography

Abstract

A magnetic graphene quantum dot (MGQD) nanoparticle, synthesized by hydrothermally reducing and cutting graphene oxide-iron oxide sheet, was demonstrated to possess the capabilities of simultaneous confocal fluorescence and magnetomotive optical coherence tomography (MMOCT) imaging. This MGQD shows low toxicity, significant tunable blue fluorescence and superparamagnetism, which can thus be used as a dual-modality contrast agent for confocal fluorescence microscopy (CFM) and MMOCT. The feasibility of applying MGQD as a tracer of cells is shown by imaging and visualizing MGQD labeled cells using CFM and our in-house MMOCT. Since MMOCT and CFM can offer anatomical structure and intracellular details, respectively, the MGQD for cell tracking could provide a more comprehensive diagnosis.

Recent Advances on Graphene Quantum Dots for Bioimaging Applications

“…In contrast to Fl/MRI, Li et al reported on superparamagnetic GQDs (MGQDs) as a dual-modal contrast agent for Fl/optical coherence tomography imaging (Fl/OCT) (Li et al, 2019). The MGQDs internalized into 3T3 exhibited blue fluorescence as revealed by in vitro CLSM imaging (Figure 14A), while for OCT, the MGQD-labeled cells were placed on an agar gel to mimic the human soft tissues, and then imaged by an in-house magnetomotive OCT system.…”

Molecular Contrast Optical Coherence Tomography and Its Applications in Medicine

“…Another advantage of MM-OCT is that it can use MRI contrast agents, in which SPIONs have been approved by FDA. The development of novel magnetomotive contrast agents is relatively easy [ 98 , 99 , 100 ]. Besides, many synthesized magnetic microspheres have been developed as efficient contrast agents for multiple imaging modalities, for instance, MM-OCT and fluorescence [ 101 ].…”