Study of dissolved oxygen sensing characteristics of hydrogel optical fiber based on fluorescence quenching method

In this paper, hydrogel optical fiber doped with fluorescent indicator was used to detect dissolved oxygen (DO) based on fluorescence quenching method. Polyethylene glycol diacrylate (PEGDA) was used as precursor and 2-hydroxy-2-methyl-phenylacetone as photoinitiator to fabricate the hydrogel optical fiber. Fluorescent indicator was doped into the core and cladding of the hydrogel optical fiber separately to optimized the DO sensing characteristics. Experiment results show that the two kinds of hydrogel optical fiber have good repeatability. Compared with the core doped fiber, the loss of the cladding doped fiber decreased from 4.2468 +/- 0.1396 dB/cm to 1.3193 +/- 0.0355 dB/cm, the response time to DO dropped from 15 min to 10 min, and the detection limit of dissolved oxygen decreased from 0.18 mg/L to 0.17 mg/L. However, due to the weak interaction between the fluorescent indicator and the evanescent wave in the cladding, the sensitivity decreased and the value of I-0/I decreased from 3.47 to 2.12. Due to excellent permeability and biocompatibility of PEGDA, the prepared hydrogel optical fiber is very promising for detection dissolved oxygen in biomedical area.