A novel low-cost and simple fabrication technique for a paper-based analytical device using super glue.

BACKGROUND

The microfluidic paper-based analytical devices (μPADs) have been highly regarded as effective tools that offer a cost-effective and portable solution for point-of-care testing (POCT) and on-site detection. Utilizing paper substrates such as cellulose and nitrocellulose membranes, μPADs have proven beneficial for a range of applications from medical diagnostics to environmental monitoring. Despite their advantages, the fabrication of μPADs often requires sophisticated techniques and equipment, posing challenges for widespread adoption, especially in resource-limited settings. This study addresses the need for a simplified, low-cost method for fabricating μPADs that is accessible without specialized training or equipment.

RESULTS

This research introduces a novel, efficient method for producing μPADs using 3D-printed slidable chambers and super glue vapor, bypassing traditional, more complex fabrication processes. The method utilizes super glue (ethyl-cyanoacrylate) vapor to create hydrophobic barriers on paper substrates. By optimizing the exposure sequence to super glue and water vapors and the heating conditions, we achieved rapid hydrophobization within 5 min, creating effective hydrophobic barriers and hydrophilic channels on paper substrates. The technique's simplicity allows for use by individuals without specialized training. The practical application of the fabrication method is demonstrated by the fabrication of μPADs that can detect multiple target analytes. We perform the simultaneous detection of glucose, proteins, and also the simultaneous detection of heavy metal ions nickel (Ni) and copper (Cu), highlighting its potential for broad applications in point-of-care diagnostics.

SIGNIFICANCE

This study is the first to report a method for selective exposure of ethyl-cyanoacrylate vapor for the fabrication of μPADs. This method significantly reduces the complexity, time, and fabrication cost, making it feasible for use in various settings. It also eliminates the need for specialized equipment and can be executed by individuals without specialized training. We believe that the proposed fabrication method contributes to the wider adoption and deployment of μPADs across various sectors.