Ultrabright difuranfluoreno-dithiophen polymers for enhanced afterglow imaging of atherosclerotic plaques

Cardiovascular diseases, including stroke driven by atherosclerosis, remain a leading global health concern. Current diagnostic imaging modalities such as magnetic resonance imaging fail to characterize oxidative stress within atherosclerotic plaques. Here, we introduce difuranfluoreno-dithiophen-based polymers designed for afterglow imaging, offering ultrabright luminescence, ultralow-power excitation (0.087 milliwatts per square centimeter), and ultrashort acquisition times (0.01 seconds). Through a molecular engineering strategy, we have optimized polymers for enhanced reactive oxygen species (ROS) generation capability, ROS capturing capability, and fluorescence quantum yield, resulting in an increase in afterglow intensity (~130-fold) compared to commonly used 2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene polymer (MEHPPV). Additionally, we have developed ratiometric afterglow nanoparticles doped with oxidative stress-responsive molecules, enabling imaging of oxidative stress markers in atherosclerotic plaque. This approach provides a tool for cardiovascular imaging and diagnostics, which is conducive to the auxiliary diagnosis and risk stratification of atherosclerosis.