Organic radical materials in biomedical applications: State of the art and perspectives

Organic radicals usually show unique chemical reactivities and paramagnetism, which have aroused wide concern in physical, chemical, and biological fields for many years. Here we summarized the biomedical applications of radical-containing materials in imaging/sensing (e.g., EPR imaging, spin labeling, magnetic resonance imaging, and fluorescence imaging ) and photo-triggered therapies (photodynamic therapy and photothermal therapy). We introduced the fundamental characteristics of representative organic radical materials and highlighted their design principle and working mechanism with reference to these biomedical uses.


Owing to their unique chemical reactivities and paramagnetism, organic radicals with unpaired electrons have found widespread exploration in physical, chemical, and biological fields. However, most radicals are too short-lived to be separated and only a few of them can maintain stable radical forms via stereochemical strategies. How to utilize these raw radicals for developing stable radical-containing materials have long been a research hotspot for many years. This perspective introduces fundamental characteristics of organic radical materials and highlights their applications in biomedical fields, particularly for bioimaging, biosensing, and photo-triggered therapies. Molecular design of these radical materials is considered with reference to their outstanding imaging and therapeutic performances. Various challenges currently limiting the wide applications of these organic radical materials and their future development are also discussed.

Author list:

Xiao Cui, Zhen Zhang, Yuliang Yang, Shengliang Li*, Chun-Sing Lee*

How to cite:

X. Cui, Z. Zhang, Y. Yang, S. Li, C.-S. Lee, Exploration 2022, 2, 20210264.