Figure 3.

Autonomous sequential fluid delivery in a 2DPN. Each leg wicked fluid from a single buffer source, and dried dyes representing reagents create different fluids from each leg (colours). Each coloured fluid arrived at a different time at the “detection zone” (green box) and was shut off in a timed sequence after delivery. Some “bleeding” from the cellulose reagent pads can be seen as a narrow band that occupies about 20% of the strip width. Time courses show colour across the full strip width or the detection zone as a function of time after device activation. Device dimensions are given in Figure 2. For perspective, the 2DPN shown here is ~2.5-fold larger in area than a conventional LFT (e.g., LFT: 5mm x 40mm = 200mm²; 2DPN paper area: 500mm²), but smaller devices (2DPN and well) can be made if desired.