Abstract: Enzyme electrodes having the enzyme enclosed within liposomes supported on, or in a membrane and immobilized therein are provided. The liposomes may be made using lipids and conveniently by "reverse phase evaporation". The enzyme electrodes incorporate conventional electrode elements, e.g., THE Clark electrode pair (Platinum/Silver) and additional membranes or screens, and used particularly in amperometric measurements. The enzyme can be an oxidase and is useful for measurement, directly or indirectly, of low molecular weight species generated by enzymic action, and effective for study of biological fluids.