Development of organic RPL dosimeters based on fluorescent products of the radiation-induced reaction of 2′,7′-dichlorofluorescein diacetate

Abstract

In this study, we achieved a shift in the fluorescence wavelength of the organic molecules by X-ray irradiation and fabricated organic materials for radiation dosimetry, focusing on the radiation-induced radical oxidation of 2′,7′-dichlorofluorescein-diacetate (DCFHDA). We doped DCFHDA into processable and transparent polymers to develop a novel tissue-equivalent dosimeters with 3D measurement capabilities. Photoluminescence spectra of the organic materials were measured before and after X-ray irradiation, and their sensitivities to X-rays were compared based on the changes in their fluorescence intensity. Fluorescent molecules were produced from DCFHDA upon X-ray irradiation, and the material was sensitive to X-rays at doses of up to 6 kGy. Furthermore, trichloroacetic acid doping enhanced the dose sensitivity of the material by promoting the radical reaction, which indicates that it can be used as a sensitizer. These results indicate that the fluorescence wavelengths of DCFHDA switched to those of another fluorescent molecule, i.e., the achievement of radiophotoluminescence (RPL). We achieved an organic RPL (ORPL) and showed the possibility of ORPL that can be utilized in dosimetry in radiotherapy.