Device

An analyte monitoring device 2 for use in contact with the skin 4 comprises a porous membrane 6 comprising an enzyme. Preferably glucose or lactate are detected via a reaction using glucose oxidase or lactate dehydrogenase to yield hydrogen peroxide which is subsequently detected using an electrode 8. Preferably the porous membrane is polyethersulfone or nylon 6, 6 such as Biodyne A or C membrane. Preferably the membrane forms a three dimensional matrix of enzyme having a thickness of less than 300 µm and the average pore size is around 0.3 µm to 0.5 µm. Preferably use of the device is preceded by an additional step such as iontophoresis, ultrasound or microneedle microporation. Methods of use of the device to continuously monitor an analyte such as glucose are disclosed.