SCS Colloquium - Micro and Nanopatterning of Surfaces to Mimic Nature Event as iCalendar

13 March 2017

4pm

Venue: ClockT018 (105-108)

Host: School of Chemical Sciences

Prof  Heather D. Maynard.fw

Presenter: Prof  Heather D. Maynard

Department of Chemistry and Biochemistry and California NanoSystems Institute, University of California, Los Angeles

Patterning proteins on surfaces at the micro- and nanoscale is important for many applications including as biointerfaces in tissue engineering and in sensors.  Electron-beam (e-beam) lithography is a powerful patterning technique, capable of fabricating nanometer features with nanometer alignment accuracy.  We have developed several ways of patterning proteins on surfaces with e-beam lithography including indirect and direct techniques. For example, poly(ethylene glycol)s (PEGs) synthesized with biotin, aminooxy, maleimide, and nitrilotriacetic acid (NTA) end groups are readily patterned on surfaces.  As a result, proteins conjugated to the surface features via ligand binding sites, N-terminal oxoamides, free cysteines, and histidine tags, respectively.  Patterns of different proteins side-by-side and in three-dimensional arrangements are readily made. More recently, we developed a novel trehalose glycopolymer resist that protects proteins during electron-beam exposure.  This negative resist allows for direct-write patterning of single and multiple proteins at the micron and nanometer scale. The resist stabilizes proteins to the vacuum and irradiation steps to produce bioactive surfaces.  Patterning of enzymes (glucose oxidase and horseradish peroxidase), growth factors (vascular endothelial growth factor and basic fibroblast growth factor), and immunoglobulins (horse IgG, chicken IgG, and human IgG) were made.  These were patterned singly and together at both the micron and nanometer scales, with features as small as 80 nm.  Furthermore, this direct-write protein patterning technique was demonstrated in an in vitro biosensor application. Surfaces with well-defined protein patterns were generated for the direct capture and detection of released cell-signaling molecules or cytokines. Fabrication of the surfaces and applications in enzyme cascades, cell adhesion, sensors, and encryptic messages will be discussed.

 

Colloquium will be followed by a reception at 5 pm in 302-Level 10 common room