Fabrication of a Paper-Based Microfluidic Device to Readily Determine Nitrite Ion Concentration by Simple Colorimetric Assay

Paper-based microfluidic devices (µPAD) are a burgeoning platform of microfluidic analysis technology. The method described herein is for use in undergraduate and high school chemistry laboratories. A simple and convenient µPAD was fabricated by easy patterning of filter paper using a permanent marker pen. The usefulness of the device was demonstrated by determination of nitrite ion concentration employing a colorimetric assay. The results for real sample detection using this µPAD were satisfactory and show promise for use in other applications.