Abstract: This invention belongs to the field of optical chemical sensors. Specifically, it relates to sensors based on the absorbance and emission of light by an indicator molecule where the optical properties of the indicator molecule change in response to a particular analyte. These indicator molecules are immobilized in a transparent substance that is exposed to light, where the substance is typically a solid such as a sol-gel or a polymer. More specifically, it is a new process for manufacturing a material (a medium or matrix) to hold or encapsulate sensing molecules. This new material has an improved resistance to exposure to hydrocarbons. These materials are used to immobilize colorimetric and/or fluorescence indicators in a matrix that repels hydrocarbons in general and non-polar hydrocarbons (i.e. aromatics hydrocarbons) in particular.

Abstract: A porous glass optical fiber sensor, a method for its use, and a method for its manufacture. The sensor includes a glass optical fiber for conveying light, the fiber having a surface of interconnected and permeable chambers within the fiber, for optically sensing within the chambers. An indicator can be applied to the surface for sensing. The sensor is made by: first, drawing the fiber; second, heat treating the fiber to induce phase separation; and third, leaching a phase from the fiber. Thereafter, an indicator, such as a pH or moisture indicator, can be applied to the fiber for sensing. The sensor is used in conjunction with a light source, a light detector, and means for measuring change in the light caused by an agent within the porosity of the sensor.