Fig. 1. EPR spectra of profluorescent nitroxide probe (a), silicone rubber (b), and silicone rubber with profluorescent nitroxide probe (c) with different absorbed doses; normalized total radical concentrations of profluorescent nitroxide probe and silicone rubber with profluorescent nitroxide probe with different absorbed doses (d) (color online)

Fig. 2. Infrared spectra of the alkanes released from (a) silicone rubber and (b) silicone rubber with profluorescent nitroxide probe before and after γ radiation; (c) curves of alkane peak areas with different absorbed doses (color online)

Fig. 3. Schematic diagram of how coumarin-based profluorescent nitroxide probe reacts with the radical produced by irradiated silicone rubber to show fluorescence enhancement

Fig. 4. (a) Fluorescence spectra (λ_ex = 365 nm) of the SR-P samples with different absorbed doses; (b) emission intensity alternation ratio I_m/I₀ versus absorbed doses (color online)