Disposable sensors in diagnostics, food and environmental monitoring

Disposable sensors are low‐cost and easy‐to‐use sensing devices intended for short‐term or rapid single‐point measurements. The growing demand for fast, accessible, and reliable information in a vastly connected world makes disposable sensors increasingly important. The areas of application for such devices are numerous, ranging from pharmaceutical, agricultural, environmental, forensic, and food sciences to wearables and clinical diagnostics, especially in resource‐limited settings. The capabilities of disposable sensors can extend beyond measuring traditional physical quantities (for example, temperature or pressure); they can provide critical chemical and biological information (chemo‐ and biosensors) that can be digitized and made available to users and centralized/decentralized facilities for data storage, remotely. These features could pave the way for new classes of low‐cost systems for health, food, and environmental monitoring that can democratize sensing across the globe. Here, a brief insight into the materials and basics of sensors (methods of transduction, molecular recognition, and amplification) is provided followed by a comprehensive and critical overview of the disposable sensors currently used for medical diagnostics, food, and environmental analysis. Finally, views on how the field of disposable sensing devices will continue its evolution are discussed, including the future trends, challenges, and opportunities

Anti-inflammatory effects of eugenol nanoemulsion as a topical delivery system

Eugenol is the main constituent of clove oil with anti-inflammatory properties. In this work, for the first time, O/W nanoemulsion of eugenol was designed for the evaluation of anti-inflammatory effects as a topical delivery system. Topical formulations containing 1, 2 and 4 of eugenol as well as a nanoemulsion system containing 4 eugenol and 0.5 piroxicam were prepared. Further to physicochemical examinations, such as determination of particle size, polydispersity index, zeta potential and physical stability, anti-inflammatory activity was examined in carrageenan-induced paw edema in rats. The optimum formulation was found to contain 2 eugenol (oil phase), 14 Tween 20 (surfactant) and 14 isopropyl alcohol (co-surfactant) in water. Nanoemulsion with polydispersity index of 0.3 and median droplet diameter of 24.4 nm (d50) was obtained. Animal studies revealed that the nanoemulsions exhibited significantly improved anti-inflammatory activity after 1.5 h, compared with marketed piroxicam gel. Additionally, it was shown that increasing the concentration of eugenol did not show higher inhibition of inflammation. Also, the nanoemulsion having piroxicam showed less anti-inflammatory properties compared with the nanoemulsion without piroxicam. © 2015 Taylor & Francis