Enhanced X-ray Dose Response of Radio-fluorescent Hydrogels Enabled by Persulfate Salts

Coumarin 3-carboxylic acid (CCA)-loaded radio-fluorescent hydrogels have attracted interest for ionizing radiation dosimeters, but their sensitivity needs to be improved. In this study, we added ammonium persulfate (APS) to a polyacrylamide (PAAm)-CCA hydrogel. The introduction of APS improved the hydrogel dose sensitivity to 336.02 Gy^- 1, which is 1.8 times that of the counterpart without APS. Our hydrogel can measure the X-ray dose in a range of 0 - 15 Gy with a lower limit of detection (LOD) of 0.1 Gy. Additionally, the hydrogel can sense X-ray doses within a wide range of the dose rate and temperature, and the dose‒response can be well retained 7 days postirradiation. Therefore, we think this study provides a simple and robust method to improve the sensitivity of CCA hydrogel dosimeters, presenting great potential in clinical radiotherapy.