Comment on: “Dissolved oxygen sensing characteristics of plastic optical fiber coated with hydrogel film” – The wider context of fibre optic oxygen sensing

•Ruthenium-based fiber optic oxygen sensors need protective coating and leaching studies before they can be safely used in clinical settings.•Coatings on fiber optic oxygen sensors can reduce the rate of oxygen diffusion, and increase their response time.•Oxygen sensors with a response time shorter than 1 s are required for the study of rapidly changing biological phenomena, for which oxygen sensors based on platinum porphyrin luminophore may facilitate translation to the bedside.•Oxygen sensors based on platinum porphyrin luminophore may facilitate translation to the bedside.