New film dosimeters PVA/(DCP/CR) and PVA/(DCP/BPR) have been prepared through the casting method. The colorimetric properties of both films changed from violet to pink and from green to yellow with exposures to gamma rays between 0–80 and 0–40 kGy, respectively. The color response was accelerated with chloral hydrate to half of the radiation dose between 0–40 and 0–20 kGy for both systems, respectively. The UV–visible spectrophotometer shows outstanding stability of the prepared dosimetric systems. Relative humidity was studied and the response indicated that both films possess very good stability during irradiation. Graphical abstract

In this study, two separate hydrogel dosimeters were prepared for low-dose measurement. The first system is based on Congo Red (CR) dye and a blend of natural polymers (gelatin/CMC) while the second system is based on 2,6-dichlorophenol indophenol (DCP) blue dye and a hybrid polymer blend (PVA/gelatin/CMC). The sensitivity of Congo red (CR)–(gelatin/CMC) gel dosimeter and 2, 6 – di choro phenol indophenols(DCP)-(PVA/gelatin/CMC) gel dosimetry systems were examined by studying the comparative results between the two different systems through the change in optical properties upon exposure to different gamma radiation doses, which showed the sensitivity of the second system (DCP)-(PVA/gelatin/CMC) to radiation is more than the first system(CR)–(gelatin/CMC) (CR) and (DCP)dyes have absorbance crest at 492 and 622 nm respectively. With the increase of the radiation dose, the decomposition of the dyes increases, and thus the color of the prepared hydrogel changes from orange to colorless in the case of (CR) dye at the dose (0–3.5 kGy) and from blue to colorless in the case (DCP) dye at the absorbed doses ranged from (0–1000 Gy). Dose-response curves, sensitivity, FTIR analysis, and the relative stability of the prepared hydrogel before and after irradiation were studied.