FIG. 19.

Paper plates created using photolithography for multizone assays. The procedure to pattern an SC (cyclized poly(isoprene) derivative) photoresist includes these steps: to begin, the sheets of paper were first impregnated with the SC photoresist. The photoresist was allowed to dry and was exposed to UV light through a transparency mask. After UV exposure, the paper was developed using the appropriate solvent, and then the photoresist was dried at 25 °C for 1–2min. (a) 96-zone plate after a range of volumes (1–55 μl) of solutions of different dyes were applied to alternating zones. This depicts the fluidic isolation of the various zones. (b) A 96-well plate that a volume of 55 μl of fluid was restricted from flowing over the hydrophobic barriers. (c) Alternative design for the 96-well plate that contains connection channels between zones. Every nine zones are connected with channels to a central zone. The Coomassie Brilliant Blue G250 solution was applied to the top row and the Amaranth solution was applied to the bottom row. The Amaranth spreads evenly while the G250 interacts better with the paper. The middle row, the reagents were able to interact in a third zone. (d) A time-lapse of the mixing of two solutions and the reaction in (c); the color change occurs only minutes after the application of the two different solutions.¹⁴⁶ Reproduced with permission from Carrilho et al., Anal. Chem. 81(15), 5990–5998 (2009). Copyright 2009 American Chemical Society.