Studying the adsorption of blood plasma proteins at the solid/liquid interface is vital to understanding blood/materials interactions of polymeric prosthetic devices. In this project the electromagnetic field at the surface of thin film integrated optical waveguides will be used to excite fluorescence and Raman scattered emission in proteins adsorbed to the polymer/solution and glass/solution interfaces. Protein fluorescence is a proven method for studying the kinetics of adsorption and total adsorbed amount. Raman spectroscopy is the preferred vibrational technique for conformational studies of aqueous protein solutions. Thin film integrated optical (lO) devices possess an """"""""optical streak"""""""" of excitation energy at the waveguide surface. This streak results from the approximately 500 total internal reflections per cm of an incoupled light beam as it propagates down the waveguide. The lO geometry thus offers a large and efficient interfacial excitation volume accompanied by a signal enhancement factor of up to 200 fold. This proposal contends that thin film lO waveguides will 1) yield a stronger protein fluorescence signal at lower laser power than that obtained by conventional total internal reflection methods, and 2) produce Raman scattered spectra from adsorbed protein films. Prism coupled 1-3 micron films of sputtered 7059 Corning glass or spun cast polymer films on quartz microscope slides will serve as the waveguides. The proteins will be delivered to the waveguide surface via a flow cell device. The fluorescence studies will use fluorescein labeled lgG and serum albumin. The Raman studies will use hemoglobin for resonance Raman and unlabeled lgG and serum albumin for spontaneous emission. The additional spectral sensitivity required for a successful Raman experiment will be provided by using a nitrogen cooled charged-coupled device array detector.
|Throne, R; Wilber, D; Olshansky, B et al. (1993) Autoregressive modeling of epicardial electrograms during ventricular fibrillation. IEEE Trans Biomed Eng 40:379-86|