Printed Low-Cost Microfluidic Paper-based Analytical Devices for Quantitative Detection of Vitamin C in Fruits

Microfluidic paper-based analytical device has been fabricated and subsequently applied to determine the Vitamin C level of the non-seasonal fruit i.e pineapples, oranges, guavas, and apples in Indonesia. uPAD was prepared by creating a hydrophobic barrier on Whatman Chromatography paper No. 1 in a certain pattern printed using Xerox Colorcube 8580 DN-2. 0.05 ul of 2,6-Dichlorophenolindophenol was dispersed into a detection area on the uPAD devices prior to the addition of 0.2 ul of fruits juice samples. The barrier allowed the fruits juice to flow and alter the color of the reagents through a redox reaction. Vitamin C in fruit juice altered the color of 2.6-Dichlorophenolindophenol reagent into a pinkish color. The changing of the reagent color was then processed using Image J software to determine the RGB intensity level. The results showed that the average amounts of Vitamin C in pineapples, oranges, guavas, and apples are 0.05%, 0.05%, 0.08%, and 0.04% respectively.