High Speed Atomic Force Microscopy for Real Time Imaging of Biological Processes

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

Abstract In all of its forms, the microscope is the most widely used tool in the investigation of biological structure and function. The study of living and moving biological systems, with sub-second time scale resolution and with nanometer length scale resolution, is becoming increasingly important in biological research. A critical example of biological research that requires faster, high resolution imaging of dynamic processes is the degradation of cellulosic materials by enzymatic, chemical, and physical processes. Improved cellulose degradation is an important step to efficient ethanol production and will likely be critical to the nation for development of a sustainable supply of fuel suitable for transportation. This project is to develop a system, based on the Atomic Force Microscope (AFM), for nanometer scale imaging of biological samples that is several orders of magnitude faster than current AFMs. The project will develop both new methodologies and instrumentation for the real-time and high-resolution imaging of dynamic biological processes. The project addresses a critical limitation for the AFM research community, while building upon the advances of current high-speed AFM systems. The technological advancement of this fast-scanning AFM is an active, self-actuating microcantilever. The system will also utilize a novel passivation scheme to provide robust operation in all liquid environments encountered in biological imaging. Moreover, the dimensions of the active probe will be miniaturized, to retain fast dynamics as well as delicate operation. The application of this fast-scanning system will be the real-time imaging of the degradation of cellulose by the cellulase enzyme from the fungus Trichonderma reesei. This system will visualize the mechanism of degradation and determine the kinetics of this process. The broader impact of this research will be to radically improve the characterization methods available to scientists and engineers working in biology and biotechnology. High speed scanning systems operating in microscopy labs across the country, where biologists could utilize video rate atomic force microscopy to obtain the fastest and highest resolution images of dynamic biological processes, would be enabled by this project. The microscope will also be capable of high speed molecular recognition for surface characterization of lipid membranes, proteins and molecular motors, cells and other biological systems. The initial step will be an investigation of the kinetic interactions between cellulose and cellulases, with the aim of improving production of cellulosic ethanol. An overarching priority for these advancements is to produce technology that is transferable to other commercial AFM systems, directly enabling the scanning probe research conducted at various research and industry labs. With the contributions of this project, dynamic, nanoscale imaging and manipulation can be extended to video rates, in a manner akin to scanning electron microscopy or video optical microscopy. The proposed program will also create educational opportunities for students to learn about the interface between physical science, biological science, and nanotechnology by focusing on graduate training, undergraduate involvement, and K-12 outreach efforts.