Advances on microfluidic paper-based electroanalytical devices

Since the inception of the first electrochemical devices on paper substrates, many different reports of microfluidic paper-based electroanalytical devices (mu PEDs), innovative hydrophobic barriers and electrode fabrication pro-cesses have allowed the incorporation of diverse materials, resulting in different applications and a boost in performance. These advancements have led to the creation of paper-based devices with comparable performance to many standard conventional devices, with the added benefits of pumpless fluidic transport, component sep-aration and reagent storage that can be exploited to automate and handle sample preprocessing. Herein, we review mu PEDs, summarize the characteristics and functionalities of mu PEDs, such as separation, fluid flow control and storage, and outline the conventional and emerging fabrication and modification approaches for mu PEDs. We also examine the recent application of mu PEDs in biomedicine, the environment, and food and water safety, as well as some limitations and challenges that must be addressed.