New techniques to dramatically extend the sensitivity and resolution in imaging biological specimens using novel methods of optical excitation and manipulation of biological materials on solid surface will be developed. The controlled penetration depth of optical excitation in evanescent wave fluorescence will be combined with ordered arrays of biological molecules on solid surfaces, allowing high-resolution optical sectioning of analytes bound specifically to biomolecules. By so extending Total Internal Reflection Fluorescence (TIRF) with sensitive vertical sectioning, two significant hurdles will be overcome: First, by distinguishing between analytes bound specifically to the surface and those adhered non-specifically, enhancement in sensitivity by an order of magnitude and hence selectivity is expected in solid-phase assays. Second, the extension of evanescent fluorescence techniques with vertical sectioning to unprecedented resolution levels (in the order of 10 nm) will allow for the development of many novel and powerful diagnostic techniques. Utilizing modern optoelectronics and single-mode optical waveguides, the complexity and ultimate cost of the detection apparatus will be reduced, making possible the application of these techniques to a wide variety of bioanalytical assays.
