(232g) A Colorimetric Plasmonic Nanosensor Hydrogel for the Detection of Spatial Dose Deposition of Ionizing Radiation for Clinical Radiotherapy

Complicated radiotherapy techniques are used to deliver radiation dose to the tumor site without causing heavy damage to the surrounding healthy tissue. This delivered dose is recorded and monitored to improve the wellbeing and quality of the patient. Contemporary sensors require highly trained professionals to operate and are very cumbersome to use. In this talk, we discuss a novel colorimetric sensor that can detect therapeutic levels of ionizing radiation. This is accomplished by the conversion of Au+ ions to a characteristic pink color of gold nanoparticles in a hydrogel matrix with the help of cationic micelles and ionizing radiation. A significant increase in the intensity of the pink color was observed with increasing the radiation dose. This color difference in the intensity was quantified using Ultraviolet-Visible spectroscopy and was used as a qualitative and quantitative indicator of the delivered dose. Also, a curing agent was allowed to diffuse into the hydrogel matrix which helped render a spatial dose monitoring capability to the nanosensor. The gel dosimeter was able to detect doses in the therapeutic range for conventional radiotherapy, making it clinically viable. This clinical viability of the nanosensor was successfully studied on canine patients undergoing radiotherapy. The hydrogel nanosensor was also successfully able to detect low doses of radiation when employed for the detection of radioactive isotopes in clinical settings.