Nanofiber adhesives and their uses with device, such as medical devices, are described. In one embodiment, a nanofiber adhesive layer may be disposed on a surface of a medical device, such as a backing layer of a sensor, for adhesion to a substrate. The nanofiber adhesive layer may allow durable adhesion to the substrate. Other described features may include materials and methods to determine the attachment of the medical device to a patient by determining the adhesive state of the adhesive layer.