(168i) Generation of Plasmonic Nanoparticles in an Amino Acid Incorporated Hydrogel for Detection of Low Doses of Ionizing Radiation

Radiotherapy has shown immense therapeutic value to treat cancerous lesions inside the body. The radiation treatment of a patient is a multi-stage complex process that requires a high level of accuracy. Even with the quality assurance that is performed prior to treatment, there are significant causes for failure in delivering the prescribed radiation dose including equipment failure and operating error. The existing technology to measure these doses requires trained personnel to operate and complex read out mechanisms making their routine use sparse. To alleviate these concerns we have developed a colorimetric sensor that changes color upon exposure to ionizing radiation. We use the free radical species generated through radiolysis of water to reduce the metal ions to metal atoms which further nucleate and grow into nanoparticles templated by amino acids. This sensor has been incorporated in a hydrogel to mitigate handling and storage concerns. The generated nanoparticles in the hydrogel were quantified through Ultraviolet-Visible Spectroscopy. We observed that the yield of nanoparticles was proportional to the radiation dose and was used to quantify the delivered radiation dose. Transmission Electron Microscopy and Dynamic light scattering was used to quantify the size of the nanoparticles. Finally, we show the sensors capability in a canine patient that was undergoing treatment. Our predictions using our sensor matched the expected prescribed dose. The ease of operation of the colorimetric sensor makes it a potential candidate during clinical radiotherapy.