Wearable Nanoplasmonic Patch Detecting Sun/UV Exposure.

Sun exposure is known to yield beneficial health outcomes, including synthesis of adequate levels of vitamin D and beneficial modulation of blood pressure, and it is a valuable factor in mental health care. However, the increasing incidence of sun/UV exposure-related illness, such as skin cancer, is seriously concerning public health authorities as well as the scientific community. Consequently, moderate sun/UV exposure is strongly recommended. A wearable nanoplasmonic patch whose original color changes upon sun exposure due to its UV-responsive capabilities that are visually detectable has been engineered. The main scaffold of this patch is made of nanopaper, which is a flexible, lightweight, optically transparent and biocompatible material. Moreover, its UV-responsive agent is based on silver nanoparticles (AgNP), whose nanoplasmonic properties and safe use in bioapplications are widely covered in the literature. As UV light can modulate the size of AgNP significantly, the nanoplasmonic properties of the AgNP-decorated nanopaper are also modulated leading to a change in color, which is readily observable upon sun exposure. This facilitates that the users can be alerted to moderate sun exposure and may prevent skin damage. Given the transparent nanoplasmonic nature of the resulting device, after 15 min of artificial sunlight exposure, the change in color of the patch was proven more observable in skins with the highest and moderate risk of developing skin cancer (skin types I, II, III, and IV) than in skin types V and VI-which are reported to tolerate relatively high levels of sun exposure safely. This low-cost wearable device is amenable to facilitating healthcare in low-resource settings using biomaterials and nanoplasmonics.