Colorimetric sensors can be used for the detection of radiation levels delivered to radiotherapy patients.

Images of hydrogels following exposure to different doses of ionizing (X-ray) radiation. Formation of gold nanoparticles renders a maroon color to the gel.

The accompanying image is of a hydrogel following exposure to different doses of ionizing (X-ray) radiation. Formation of gold nanoparticles renders a maroon color to the gel.