|Title||A gravity-driven droplet fluidic point-of-care test|
|Publication Type||Journal Article|
|Year of Publication||2023|
|Authors||Vahabi, H, Liu, J, Dai, Y, Joh, DY, Britton, R, Heggestad, J, Kinnamon, D, Rajput, S, Chilkoti, A|
We report a simple droplet fluidic point-of-care test (POCT) that uses gravity to manipulate the sequence, timing, and motion of droplets on a surface. To fabricate this POCT, we first developed a surface coating toolbox of nine different coatings with three levels of wettability and three levels of slipperiness that can be independently tailored. We then fabricated a device that has interconnected fluidic elements—pumps, flow resistors, and flow guides—on a highly slippery solid surface to precisely control the timing and sequence of motion of multiple droplets and their interactions on the surface. We then used this device to carry out a multi-step enzymatic assay of a clinically relevant analyte—lactate dehydrogenase (LDH)—to demonstrate the application of this technology for point-of-care diagnosis.