Microfluidic paper-based analytical devices (pads) for analysis lead using naked eye and colorimetric detections

This work describes comparation two designs of a microfluidic paper-based analytical devices (PADs) using a wax printing for fabrication of hydrophobic zones on the chromatographic paper and their application to the detection of lead in waste samples. Two different designs used in this research were distance-based method and analysis image method. Sodium rhodizonate in tartrate buffer solution (pH 2.8) solution are used as the colorimetric reagents for the direct naked eyed detection of lead(II) on PADs. The detection of lead(II) concentration is conducted by measuring the distanceof a colored reaction product which propagate in the detection zone (design 1) and the change in color intensity on the PADs is also used for the lead detection using ImageJ software to determine the RGB value (design 2). Related to both methods can be used to determine the concentration of lead(II) with a comparable coefficient of determination, but based on the analysis method, design one is a design that is very simple, easy, fast, inexpensive and only uses the naked eye for detection.