3D printed hydrophobic barriers in a paper-based biosensor for point-of-care detection of dengue virus serotypes

Paper-based biosensor is one of the most commonly used platforms for point-of-care testing (POCT). Among these platforms, microfluidic paper-based analytical devices (mu PADs) have the most versatile designs due to the different hydrophobic barrier patterns and layers of the devices. In addition, mu PADs can also be used in com-bination with other biosensor platforms to improve the performance of the device. Simple and convenient methods for fabricating low-cost and design-adjustable hydrophobic barriers on paper are one of the most challenging aspects for creating mu PADs. This work demonstrated a simple technique for using the common polylactic acid (PLA) filament and wax filament to create hydrophobic barriers on paper for mu PADs using a commercialized 3D printer. As a proof of concept, the papers with 3D printed PLA barrier were used in com-bination with a fluidic chip in a prototype biosensor, in which the barrier paper housed four cell-free reactions and the fluidic chip achieved sample delivery to the reactions in the device. Our designed prototype was capable of discriminating dengue virus serotypes based on small nucleotide sequence differences. The proposed com-bination of 3D-printed barrier paper and fluidic chip provides a versatile platform for rapid prototyping of POCT with possible compatibility with various detection systems.

Automated summary

This study demonstrates a simple technique for creating hydrophobic barriers on paper for muPADs using a commercialized 3D printer. The designed prototype is capable of discriminating dengue virus serotypes based on small nucleotide sequence differences, providing a versatile platform for rapid prototyping of POCT.