Abstract: A biosensor for detecting the concentration of an analyte in wound fluid, the biosensor being at least substantially free of catalase and comprising a sensing means comprising an oxidase enzyme and a hydrogen peroxide indicator means, the arrangement being such that, when a sample of wound fluid comprising the analyte is brought into contact with the sensing means, the oxidase enzyme reacts with the analyte to produce hydrogen peroxide which triggers the indicator means to indicate the presence of the analyte in the wound fluid.

Abstract: A skin dressing comprises a first dressing component (16) carrying oxidoreductase enzyme in dried condition; and a second dressing component (18) carrying a source of water, such that when the first and second dressing components are placed in fluid communication with each other, water migrates from the second component towards the first comportent and acts to hydrate enzyme carried by the first component, at least at the surface of the first component. The dressing components are kept separate before use, e.g. being sealed in separate sterile, water-impervious packages such as laminated aluminum foil pouches. In use of the dressing, the second dressing component is located on the skin of a human or animal, e.g. over a wound to be treated or on a region of skin to be treated for cosmetic or therapeutic purposes such as for treatment of acne or other skin conditions. The first dressing component is placed on top of the second component in fluid communication therewith.