The adoption of existing continuous glucose monitors (CGMs) is limited by user burden. Herein, a design for a glucose biosensor with the potential for subcutaneous implantation, without the need for a transcutaneous probe or affixed transmitter, is presented. The design is based on the combination of an enzyme‐driven phosphorescence lifetime‐based glucose‐sensing assay and a thermoresponsive membrane anticipated to reduce biofouling. The metalloporphyrin, Pd meso‐tetra(sulfophenyl)‐tetrabenzoporphyrin ([PdPh4(SO3Na)4TBP]3, HULK) as well as glucose oxidase (GOx) are successfully incorporated into the UV‐cured double network (DN) membranes by leveraging electrostatic interactions and covalent conjugation, respectively. The oxygen‐sensitive metalloporphyrin is incorporated at different levels within the DN membranes. These HULK‐containing membranes retain the desired thermosensitivity, as well as glucose diffusivity and primary optical properties of the metalloporphyrin. After subsequently modifying the membranes with GOx, glucose‐sensing experiments reveal that membranes prepared with the lowest GOx level exhibit the expected increase in phosphorescent lifetime for glucose concentrations up to 200 mg dL−1. For membranes prepared with relatively higher GOx, oxygen‐limited behavior is considered the source of diminished sensitivity at higher glucose levels. This proof‐of‐concept study demonstrates the promising potential of a biosensor design integrating a specific optical biosensing chemistry into a thermoresponsive hydrogel membrane.