Dissolved oxygen sensing characteristics of plastic optical fiber coated with hydrogel film

This paper proposes a dissolved oxygen sensing system based on PMMA plastic optical fiber covered at one end with biocompatible PEGDA (Polyethylene glycol diacrylate) hydrogel film. PEGDA, 2-hydroxy-2-methyl-propiophenone and DI water mixture was used as hydrogel precursors, and a certain concentration of oxygen-sensitive fluorescent indicator was incorporated into it. Fluorescence quenching method was used to detect dissolved oxygen in water, the doping concentration of fluorescent indicator in the hydrogel film was optimized. The experimental results indicate that the plastic optical fiber coated with hydrogel sensing film has good reproducibility, and the response time is within 10 s. The sensing characteristics of dissolved oxygen at 30 °C, 35 °C, and 40 °C were tested respectively, and the results showed that the linearity of the system is best at 35 °C. Within the range of pH 2–12, the fluorescence intensity of the fluorescent indicator is very stable. The sensor with biocompatible material is expected to be applied to the monitor of dissolved oxygen in the domain of biomedicine.