A single-film fiber optical sensor for simultaneous measurement of carbon dioxide and relative humidity.

ABSTRACT: Colorimetric measurement is a versatile, low-cost method for bio-/chemical sensing and that has importance in biomedical applications. General carbon dioxide (CO₂) sensors based on colorimetric change of a pH indicator report only one parameter at a time and are cross-sensitive to relative humidity (RH). This work describes a novel optical fiber sensor with a thin film on the distal end of the fiber, combining colorimetric measurement and a white light Fabry-Pérot interferometer (FPI) for the simultaneous measurement of CO₂ and RH. The CO₂ sensitive dye ion-pair: thymol blue and tetramethylammonium hydroxide are encapsulated inside organically modified silica forming an extrinsic FPI cavity (refractive index of 1.501 ± 0.02 and thickness of 5.83 ± 0.09 μm).

SUBMITTER: Liu L 

PROVIDER: S-EPMC8689145 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature