Application of electroosmotically-driven solution displacement for on-chip probing and characterization of protein adsorption

An alternative strategy for realizing on-chip characterization of protein adsorption is demonstrated using solution displacement with electro-osmotic flow in microchannels. The idea is illustrated by studying adsorption of bovine serum albumin (BSA) on polydimethylsiloxane surfaces. Through tracking the zeta potential change using the current monitoring technique, we quantify how the surface coverage of BSA varies with time and the BSA concentration. The Langmuir kinetic model is employed to capture the transient behavior of the adsorption and to determine both the adsorption and desorption rate constants. The Langmuir isotherm is also established in line to account for the sorption equilibrium.