Feasibility Assessment of a Fluorescein Dosimeter

Abstract

The objective of this work was to ascertain if fluorescein (a simple fluorescent molecule), could be used to create an economic radiation dosimeter. The degradation of fluorescein in water when exposed to ionizing radiation and the subsequent decrease in fluorescence intensity was investigated as an indicator of absorbed radiation. Cuvettes containing fluorescein concentrations ranging from 0.2-10μM were irradiated with doses ranging from 0.01-100 Sv using a 6MV linear accelerator (Varian Clinac® 600C). The resulting fluorescent signals were quantified generating dose-response type curves. The decrease in the fluorescence response based on absorbed dose was found to follow a 1^st order decay model. In terms of detecting an absorbed dose, a concentration of 0.2 μM fluorescein was shown to have the greatest sensitivity with a detection limit of 0.05 Sv. It is recommended that future work investigate lower concentration fluorescein solutions, in addition to varying water chemistries for potential increases in sensitivity.