A method of making a multi-layer biocidal structure includes providing a support and locating a first curable layer on the support. A second layer is located on or over the first curable layer, the second layer having multiple biocidal particles located within the second layer. The first curable layer and the second layer are imprinted in a single step with an imprinting stamp having a structure with a depth greater than the thickness of the second layer. The first curable layer is cured to form a first cured layer with a second layer. The imprinting stamp is removed.
