Publications

Monolayer Engineered Microchannels for Motor Protein Transport

Bunker, B.C.; Bachand, George B.; Manginell, Ronald P.

Here, self-assembled monolayers (SAMS) have been investigated for their ability to confine the absorption of the motor protein kinesin and direct the movement of microtubule shuttles (MTs) within channels of a lithographically patterned microfluidic device. Channels were made from gold films deposited on a silicon wafer to provide chemically distinct surfaces for the selective formation of a range of alkane thiol monolayers on channel walls. Devices were then exposed to solutions containing casein and kinesin to develop protein monolayers capable of propelling microtubules in the presence of adenosine triphosphate (ATP) fuel. Fluorescence microscopy images were used to observe the attachment of MTs to chemically distinct regions and to evaluate the ability of the various monolayer coatings to confine the movement of MTs within the channel system. Ellipsometry was used to characterize the protein adsorption characteristics of SAMS terminated with different functional groups to help establish confinement mechanisms. Finally, both anti-fouling and cationic monolayers were found to be effective in confining MT movement within the channels by controlling the adsorption or orientation of the casein buffer layers that mediate motor protein attachment and functionality.