Many problems in the chemical, materials, and biomedical sciences and engineering involve adsorption of large molecules at the solid-liquid interface. Optical waveguide lightmode spectroscopy (OWLS) is a premier technique allowing for the real-time detection of macromolecular adsorption at the solid liquid interface. The PIs group has used the OWLS technique extensively to build a research program focusing on bio-interfacial engineering. However, of the two original OWLS instruments, one no longer functions and the other suffers severely from an antiquated computer interface system. MicroVacuum, the commercial manufacturer of OWLS technology, has offered the PI a completely new instrument with a heavy discount making it economically as well as scientifically advantageous to purchase a new instrument rather than repair/ upgrade either of the old instruments.
This project provides the funds to acquire a new OWLS 210 system from MicroVacuum. The new instrument will be used i) to complete the current NSF funded project Carbon nanotubes as antimicrobial agents (CBET-0756323), ii) to begin work on four new projects, iii) as the primary experimental tool for undergraduate researchers in the PI's lab, and iv) as a teaching tool in the Yale Undergraduate Chemical Engineering Laboratory course.
Broader Impact:
A new OWLS instrument in the PI's lab will have a broad impact in several ways. Scientific impact will come from the currently funded project and four new projects. In particular, new nanoscale polyelectrolyte films will emerge that will impact areas such as separations, energy storage/delivery, cell-based diagnostics, and tissue engineering. OWLS has proven to be a straightforward technique for undergraduate researchers; their involvement in these new projects will bring forth a large educational impact. Finally, use of the new instrument is proposed for an experiment in adsorption kinetics in Yale's Undergraduate Chemical Engineering Laboratory beginning in Spring 2011.
Large molecules such as proteins and polymers tend to stick to surfaces. In certain cases, this tendency can be exploited for technological gain. Some examples include polymer adhesives in household or industrial applications, and protein layers leading to biocompatible surfaces for biomedical applications. The Van Tassel research group at Yale University investigates the nature of the sticking, or "adsorption," of large molecules to solid surfaces. A premier technique for measuring adsorption is optical waveguide lightmode spectroscopy, or OWLS. The Van Tassel group has used the OWLS method since 1997, but their current instruments had become unusable due to break down and obsolescence. The key outcome of this proposal was the purchase of a new OWLS instrument, capable of performing state-of-the-art measurements of protein and polymer adsorption for years to come. During the project window, the Van Tassel group at Yale used the new instrument on a number of projects: Polyelectrolyte adsorption to a carbon nanotube layer under an applied potential. Carbon nanotubes are very thin tube-like objects with many fascinating properties: stronger than steel, able to conduct electricity without loss of energy, etc. In many applications, it would be useful to place a polymer layer on top of a nanotube layer, and we are investigating using OWLS a possible way to do this that involves adsorption from solution in the presence of an applied electric potential. Carbon nanotube containing polymer films with antimicrobial properties. Tens of thousands of people die each year of medical device infection, and one way to reduce this number is through devices made with materials that suppress infection. Carbon nanotubes offer the possibility of highly stable, non-leachable anti-infective materials, and we are investigating the assembly of thin polymer films containing carbon nanotubes via OWLS. Porous nanofilm biomaterials. Thin films capable of being loaded with biologically active species could enable next generation medical therapies involving tissue regeneration. We are developing porous film assembly strategies through the help of OWLS. In addition to advancing our scientific knowledge, this project has provided a number of students an excellent opportunity to further their education through laboratory-based research projects.
