Multifunctional iron-doped carbon dots: Integration of fluorescence and magnetic resonance imaging for enhanced photodynamic therapy

Multidimensional imaging materials are highly sought after in scientific research and clinical applications due to their ability to provide comprehensive imaging data while minimizing experimental interference. The iron-doped carbon dots (TPFe-CDs) prepared in this study possess dual-mode imaging capabilities, combining fluorescence and magnetic resonance imaging, along with photodynamic therapy functionality. In fluorescence imaging, TPFe-CDs exhibit versatility, being effectively excited by either single-photon or two-photon excitation. This versatility enables successful imaging across various biological samples, including cells, organoids, and zebrafish. Moreover, TPFe-CDs demonstrate exceptional three-dimensional imaging capabilities, penetrating depths exceeding 300 µm, thus enabling deeper tissue imaging beyond surface layers. Additionally, TPFe-CDs serve as excellent contrast agents in magnetic resonance imaging, showcasing a T 2 relaxation rate of 10.388 mM −1 s −1 . In mouse models, magnetic resonance imaging revealed potential targeting of TPFe-CDs, primarily accumulating in the thoracic lung region, with minimal distribution observed in the gastrointestinal tract and tail regions. Furthermore, TPFe-CDs exhibit promising photodynamic therapy capabilities, generating reactive oxygen species (ROS) upon laser irradiation, leading to successful cancer cell eradication in experimental settings. The multifunctional nature of TPFe-CDs, with their dual-modal imaging capabilities and therapeutic potential, is garnering significant attention and is poised to make substantial contributions to diverse fields such as biological imaging and clinical therapy.