| A novel DNA dosimeter is investigated. The dosimeter contains short, single strands of DNA that are labeled with molecular complexes. One complex is a fluorophore that will emit light when excited. The other complex is a quencher that inhibits the fluorophore from fluorescing. When the DNA strand is intact, the fluorophore is sufficiently close to the quencher that it is not able to emit light. However, if the DNA strand is broken, the fluorophore can drift away from the quencher and subsequently fluoresce. Thus, the florescence intensity of the DNA dosimeter after exposure to ionizing radiation is an indication of the number of DNA strand breaks in the system. Radiation dose is also indicated by the fluorescence of the dosimeter as it is proportional to the rate of single strand DNA breaks.;The potential applications of the DNA dosimeter are investigated. The capabilities of the dosimeter are evaluated through a series of experiments and computer simulations, which determine the energy, particle, dose-rate, and angular response. Results are compared to the requirements of potential applications. The dosimeter is found to have no significant dependence on energy, dose-rate, and particle type. The signal response is found to be linear with absorbed dose, as predicted by the derived theory. However, the precision of the device needs further refinement for applications at absorbed dose levels less than 100 mGy, and further investigation into the cause of the observed noise is required in order to lower the limit of detection.;Keywords: radiation, dosimetry, DNA, tissue-equivalent, Forster resonance energy transfer. |
