Development of thermoplastic, flexible and biodegradable electrochemical sensors using Ecoflex® and reduced graphene oxide (rGO) for potential analysis as wearable devices

Abstract

Wearable and point-of-care devices are a promising alternative for continuous monitoring of individuals for health status and clinical diagnosis. Although many of these devices focus mainly on applications in the healthcare area, there is an increasing demand for the development of portable and easily use sensors to monitor many chemical species present in the environment. The development of conformable/moldable chemical sensors to different surfaces with easy handling and rapid response allows the monitoring and detection of various chemical species in flexible and non-plane surfaces such as in the human body and plants/food. Therefore, this project aims to develop a flexible, miniaturized, and low-cost electrochemical composite sensor from the incorporation of reduced graphene oxide (rGO) in biodegradable polymers with high flexibility, such as Ecoflex®. Subsequently, the composite films will be patterned in the electrodes format and treated superficially using a CO2 laser for the partial and localized removal of the upper polymeric layer, exposing the conductive material, and improving the electrochemical properties of the manufactured material, maintaining the device's flexibility. These processes aim to fabricate materials with excellent electrochemical performance, accessible and with minimal use of additional chemical reagents, decreasing the materials' toxicity for wearable applications, as well as providing better disposability of the sensors due to the use of biodegradable materials. As proof of applicability of these devices in analytical systems that require high sensitivity and flexibility, the sensors will be modified through the functionalization with nanomaterials as Prussian blue nanocubes and carbon nanotubes (MWCNTs-PB) and fixated in convenient platforms for the (bio)sensing of glucose in synthetic sweat and for the detection of insecticide imidacloprid directly in plants.