New metal-free molecules glow deep red in water and boost MRI contrast in test images

Bioimaging technologies, such as fluorescence imaging (FI) and magnetic resonance imaging (MRI), are powerful tools in basic research and clinical medicine. But they have drawbacks. FI allows researchers to visualize cells and other biological processes at high resolution, but it lacks imaging depth. MRI can capture images deep within the body, but it lacks the single-cell resolution provided by FI. Furthermore, MRI contrast agents contain paramagnetic metals, such as gadolinium, that can potentially cause adverse side effects.