Stable organic radical luminescent groups and their applications in nano-diagnosis and therapy

The unique singlet-state luminescence mechanism of stable organic radicals avoids the energy loss caused by inter-system crossing in traditional closed-shell molecules, providing a new approach for achieving efficient luminescence. This review focuses on systems such as poly-chlorinated triphenylmethyl derivatives (PTM, TTM, BTM, etc.), di-cyanomethyl radicals, and double radicals. Through strategies such as spatial steric hindrance, electronic delocalization, and structural regulation, their stability and luminescent properties have been significantly improved. In terms of application, organic radical materials demonstrate excellent potential for tumor treatment. Their open shell structure can generate type I reactive oxygen species through an electron transfer mechanism, effectively overcoming the limitations of tumor hypoxic microenvironment on photodynamic therapy. At the same time, their strong near-infrared absorption property enables them to have efficient photothermal conversion ability. The integrated diagnosis and treatment platform constructed through nanotechnology engineering can achieve coordinated treatment under the guidance of near-infrared imaging, providing a new material system for the development of efficient and low-toxic tumor precision treatment strategies.