An innovative Fe3+ selective ligand for Fricke-gel dosimeter

The presence of a Fe3+ selective ligand plays a key role in Fricke-gel dosimeters to preserve the 3D absorbed dose distribution. In this study, a novel Fe3+ selective ligand is proposed to overcome several limitations related to the use of the reference ligand, Xylenol Orange (XO). For this purpose, an affordable iron (III) ligand with an easy synthetic route was used. The complexation mechanism was investigated, and a single stoichiometry Fe3+-Ligand complex was identified, thus allowing a more accurate and feasible dose evaluation. The Fricke-gel dosimeter prepared with this new ligand was fully characterized by means of both optical and Magnetic Resonance Imaging (MRI) analysis. In particular, a reduction of the optical artefacts, the so-called dose threshold, and an improvement of the Signal to Noise Ratio (SNR) in MRI analysis were observed. Finally, the Fe3+-Ligand diffusion coefficient was evaluated for this innovative system and proved to be comparable to the reference ones. •Novel Fe3+ selective ligand L is proposed for Fricke gel dosimetry.•The proposed ligand allows to overcome issues of the reference one, Xylenol Orange.•The complexation mechanism of ligand and Fe3+ ions was studied via optical analysis.•Optical and MRI characterization of the new dosimetric system has been conducted.•Diffusion process was evaluated via analytical approach.