Hollow-channel paper analytical devices.
We present a microfluidic paper analytical device (μPAD) that relies on flow in hollow channels, rather than through a cellulose network, to transport fluids. The flow rate in hollow channels is 7 times higher than in regular paper channels and can be conveniently controlled from 0 to several mm/s by balancing capillary and pressure forces. More importantly, the pressure of a single drop of liquid (~0.2 mbar) is sufficient to induce fast pressure-driven flow, making hollow channels suitable for point of care diagnostics. We demonstrate their utility for simple colorimetric glucose and BSA assays in which the time for liquid transport is reduced by a factor of 4 compared to normal cellulose channels.
Department of Chemistry and Biochemistry, Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712-1224, United States.
Christophe
C
Renault
Xiang
X
Li
Stephen E
SE
Fosdick
Richard M
RM
Crooks