Method and light guide test sensor for determining an analyte in a fluid sample

An optic light guide test sensor (100) comprises a light guide (120), a reagent-coated membrane (16), and a mesh layer (22). The reagent-coated membrane (16) and the mesh layer (22) are attached to the light guide (120) at an output end (200) of the light guide (120). The light guide test sensor (100) is adapted to be used to test the level of an analyte in a biological fluid sample when used with a readhead. A method of manufacturing the light guide test sensor (100) involves providing a plurality of light guides (120), providing a strip of reagent-coated membrane (16), and providing a strip of mesh layer (22). The reagent-coated membrane (16) and mesh layer (22) are attached to the light guides (120) by ultrasonic welding to protrusions (122) located at the (200) output end. The reagent-coated membrane and mesh layer may also be attached to the light guides by adhesive.