IDBR: RUI: Development of a Cantilever Based Optical Interfacial Force Microscope

The cantilever based optical interfacial force microscope (COIFM) is a new tool to be developed, through this project, for the study bio-molecular metastable energy states. A bio-molecular system passes through several metastable states before it reaches a stable state with the lowest energy. Probing the metastable states and their shape, or conformation, is crucial for understanding bio-molecular function. However, metastable states are difficult to observe because of their relatively short lifetime and their non-equilibrium nature in a solution phase. The COIFM?s sensitive distance and force control capability will allow for investigating the metastable states along the reaction coordinates.

By combining a conventional interfacial force microscope (IFM) and an atomic force microscope (AFM) type cantilever and its optical detection scheme, the COIFM will substantive improve measurement accuracy .. A force feedback technique for the IFM will be adopted to remove the rapid snap-off process, an intrinsic mechanical instability associated with conventional devices, which prevents probing metastable states during bio-molecular activations. The smaller probe size of the cantilever will enable inproving the force resolution, over conventional techniques, by at least an order of magnitude. The improved COIFM capability will be demonstrated by probing metastable states during bio-molecular activations of a biological system at the single molecule level.

These COIFM modifications have the potential to quantitatively measure biological interactions at various molecular levels, not only for single molecules, but also for viral, bacterial, and cellular systems. To make this development as widely available to other laboratories as possible, all details, including electronic circuits and specifications of the COIFM mechanical head, will be well-documented and openly accessible. For wide applications to biological systems, manufacturers will be encouraged to incorporate COIFM capability into their existing systems. Results of the research activities will be disseminated through, and evaluated by, (i) presentations at national/international scientific conferences; (ii) publications in peer-reviewed journals; (iii) creation of an interactive physics lab website; and (iv) demonstrations to lab visitors.

This project will engage one undergraduate student and one graduate student in research and training activities each year, thus providing unprecedented research opportunities for as many as six physics, chemistry, biology, and engineering students over a three-year period. This research will be an important addition to the strong and growing multi-disciplinary undergraduate research program at Boise State University, and to its planned Biomolecular Sciences PhD program.