Abstract: A patch assembly having pre-applied pressure sensitive adhesive for semipermanent attachment to a live animal is described. This assembly permits the easy and clean attachment thereof to live animal. Further, the assembly prevents skin irritations while maintaining superior bond strength and, in turn, remaining intact and attached to the animal for extended periods of time. The invention may be used, for example, for device attachment to human and non-human animals.

Abstract: A system for detecting a specific substance or analyte of interest is provided that includes one or more sensing units and an instrument for analyzing the sensing units. Each sensing unit preferably includes a substrate, an attachment layer and at least one capture layer that includes a ligand layer. In one embodiment, the attachment layer is tripartite and includes a lower binding surface held to the substrate and an upper binding surface that holds the ligand layer, together with an insulating layer disposed between these two surfaces. The lower binding surface provides a durable and stable attachment to the substrate. The upper binding surface holds the ligand layer and does not jeopardize the integrity or viability thereof. The insulating layer prevents any unwanted interaction between the lower and upper binding surfaces. Each sensing unit is supported on a test piece received by the instrument. The instrument controllably positions the test piece using marks and/or codes on the test piece.