Protein and Gold Nanoparticle Based Radiation Sensor

High energy X-ray radiation has been used for ablation of malignant tumors for quite some time. Nevertheless, medical practitioners are unable to predict with high accuracy the amount of radiation reaching the point of interest below the tissue level. To help address this issue, we are developing a colorimetric sensor for radiation using the gold nanoparticle forming property of bio-molecules (particularly Maltose Binding Protein (MBP)) in presence of ionizing radiation. As gold nanoparticles have distinct color, gold nanoparticles formed on irradiation changes the color of the solution and thus can be used as colorimetric sensor. The color change is observed for doses of X-ray radiation as low as 2 grays (1 gray (Gy) = absorbance of 1 joule of radiation energy per kilogram of matter). The complete procedure for cloning and synthesizing MBP is also described. The system also shows a radiation dose dependent color shift (from 3 Gy to 15 Gy), which can be used to discriminate between different delivered doses.