Biodegradable polymer-based microfluidic membranes for sustainable point-of-care devices

Microfluidic paper-based analytical devices (µPADs) have gained substantial attention as portable analytical devices in various (bio)technological fields, for being affordable, user-friendly, portable, energy efficient and for allowing multiplexed analysis. Although significant progress has been achieved, there is still need for improvement in terms of performance and sustainability. In this work, a biodegradable aliphatic polyester poly(D,L-lactide-co-glycolide acid) lactide:glycolide 50:50 (PDLG), is used to produce pore- and fibre-based membranes, as alternative to conventional paper substrates. Two fabrication methods are used, with potential for industrial scale-up. The processed hydrophobic membranes are post-treated with oxygen plasma to turn them hydrophilic, allowing capillary flows. The physicochemical characterization demonstrates the suitability of the plasma-treated PDLG membranes as microfluidic substrates based on their tailorable morphologies and capillary flow rate from 36.2 ± 4.2 to 84.1 ± 5.2 mm·min−1, excellent mechanical properties and biocompatibility. Further, the membranes maintain their properties for at least 6 months when kept in vacuum and degrade quickly after their use (reaching values higher than 90 % after 6 weeks when wet). Finally, portable analytical platforms suitable for the colorimetric quantification of glucose are demonstrated. These results are of great importance for the design and manufacture of a new generation of sustainable portable analytical devices, compatible with circular economy paradigms, and a step forward to cross the challenging academia to industry barrier for their commercialization and widespread adoption.