AVS 51st International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoM

Paper BI-MoM5
Feasibility Study of a Waveguide Excitation Fluorescence Microscope for Micro and Nanoscale Characterization of Bio-Interfaces

Monday, November 15, 2004, 9:40 am, Room 210D

Session: In-Situ Spectroscopy of Biomolecules at Interface
Presenter: H.M. Grandin, Swiss Federal Institute of Technology (ETH), Switzerland
Authors: H.M. Grandin, Swiss Federal Institute of Technology (ETH), Switzerland
B. Städler, Swiss Federal Institute of Technology (ETH), Switzerland
J. Vörös, Swiss Federal Institute of Technology (ETH), Switzerland
M. Textor, Swiss Federal Institute of Technology (ETH), Switzerland
Correspondent: Click to Email
The ability to investigate the interactions that occur between a biological system and a surface, be it a native biological surface or a synthetic surface, is of critical importance to our fundamental understanding of biomaterials and their many applications in biosensors, medical implants, and tissue engineering. Our development of a Waveguide Excitation Fluorescence Microscope (WExFM) satisfies this need uniquely by providing a means for the quantitative study of bio-interfacial interactions in-situ, e.g.: protein adsorption and cell adhesion, with both temporal and spatial resolution. Although other techniques are capable of either quantitative studies, e.g.: optical waveguide lightmode spectroscopy, or of spatially resolved imaging at the interface, e.g.: total internal reflection fluorescence microscopy, the WExFM is the only technique currently available which can provide both simultaneously. Further advantages include high target sensitivity for fluorescence detection (femtoMolar range) and high surface specificity (ca. 100 nm perpendicular to the waveguide), as well as, the capability to perform multicolour imaging, large area analysis with submicron resolution, and 'built-in' calibration of fluorescent light gain. Preliminary results from streptavidin-biotin binding studies have been obtained with sub-picoMolar sensitivity, thus, demonstrating the feasibility of this technique. In this presentation the principles and experimental set-up of the WExFM will be introduced, potential applications for in-situ, real-time quantitative monitoring of protein- and cell-surface interactions will be discussed and finally, first results demonstrating the feasibility of the WExFM will be presented.