Fabrication of paper-based microfluidic device by recycling foamed plastic and the application for multiplexed measurement of biomarkers.

Microfluidic paper-based analytical devices (µPADs) are emerging as effective analytical platforms for point-of-care assays in resource-limited areas. Simple and cost-effective fabrication method still remains challenging on µPADs. A simple and cost-effective method for fabricating paper-based devices was presented in this work by using of dipping strategy with the recycled polystyrene in chloroform as the hydrophobic reagent. Adhesive tape was employed as mask to transfer the hydrophilic channel pattern to the paper substrate. With the single-sided adhesive tape stuck on the hydrophilic parts of the paper surface, the paper-based device was immersed in chloroform solution with dissolving recycling polystyrene for several seconds. Then the hydrophilic pattern can be achieved and all the other parts on the paper surface were hydrophobic. The adhesive tape was torn off from the hydrophilic parts. The highest contact angle value of 114° of the hydrophobic part was acquired with this simple fabrication method. By using of the sandwich-type immunoreactions and luminol-H2O2p-iodophenol (PIP) chemiluminescence(CL) system, three cancer biomarkers were simultaneously detected in human serum samples on µPADs with the linear range of 0.05-80.0 ng·mL-1 for carcinoembryonic antigen (CEA), 5.0-80.0 ng·mL-1 for alpha-fetal protein (AFP) and 1.0-50.0 ng·mL-1 for prostate-specific antigen (PSA). The fabricating strategy with recycling polystyrene and adhesive tape provides a versatile platform for prototyping of µPADs in both developed and resource constrained region.