Thin Film Engineering to Modulate Interfacial Interactions in Wetting, Adsorption, and Sensing

Abstract

Robustly anchored thin films provide a general approach for manipulating the properties of interfaces.  These films—often with molecular-scale thicknesses—can modulate the adsorptive properties of an underlying physical support.  Their behavior toward biological species can be related to local details such as their structure, their composition, their hydrophilicity/hydrophibicity, and their charge.  Their robustness is related to their mode of attachment and surprisingly, sometimes to their charge. On silicon substrates, siloxane (Si-O) linkages are commonly used for the attachment of molecular and polymeric films. The ability to use more chemically stable silicon-carbon linkage will be described, using both thermal and photochemical methods. Our approach has been to use these attachments as reactive centers to incorporate additional functionality. Examples include the use of surface-initiated polymerization routes (such as ATRP and ARGET) to generate non-ionic and zwitterionic thin films for use as non-fouling coatings, and for attaching receptors for biosensing. The latter has been done using porous silicon as an optical transducer, where needs to overcome fouling of this high-surface area material impact sensitivity. The benefits of a flow-through geometry for porous silicon-based sensing will be detailed.

Biography

Paul Laibinis, Professor and Chair of Chemical and Biomolecular Engineering at Vanderbilt University, focuses his research on methods of surface modification, relying heavily on methods of self-assembly, the use of thin organic films, and the determination of relationships between molecular structure and interfacial properties.  He has served on the faculties of Vanderbilt, Rice University, and MIT, all in chemical engineering.  He has received a Presidential Early Career Award in Science and Engineering, Young Investigator awards from the Office of Naval Research, the Beckman Foundation, and the Whitaker Foundation, a Camille Dreyfus Teacher-Scholar Award, and the Victor K. LaMer Award in Colloid and Surface Science from the American Chemical Society, and multiple teaching awards.  He received his undergraduate degrees in chemical engineering and in chemistry from MIT, his PhD in chemistry from Harvard working with George Whitesides, and was a post-doc at Caltech with Nate Lewis.