Dissolved oxygen sensing characteristics in blood by hydrogel optical fiber

In this paper, a hydrogel fiber optic sensing probe with a fluorescence indicator doped in the core is proposed for dissolved oxygen detection in blood. The hydrogel fiber was made by photocrosslinking with a core-cladding structure made from PEGDA precursor solutions with different concentrations. By changing the concentration of the fluorescent indicator doped in the core of the hydrogel optical fiber and changing the length of the fiber and the thickness of the cladding, the sensing performance of the fiber for dissolved oxygen was optimized, and it was found that the effect of photobleaching could be reduced appropriately by lowering the excitation power. The resolution is 0.008 ml/dl, with a linearity of 0.99, and the range is 0–2.015 ml/dl, which makes it suitable for the measurement of the partial pressure of blood oxygen in human beings. The system also shows good stability and repeatability. Due to the flexibility and biocompatibility properties, the hydrogel optical fiber dissolved oxygen sensing probe has promising application in the biomedical field.