A POROUS SILICON-BASED OPTICAL INTERFEROMETRIC BIOSENSOR

A biosensor has been developed based on induced wavelength shifts in t he Fabry-Perot fringes in the visible-light reflection spectrum oi app ropriately derivatized thin films of porous silicon semiconductors. Bi nding of molecules induced changes in the refractive index of the poro us silicon. The validity and sensitivity of the system ave demonstrate d for small organic molecules (biotin and digoxigenin), 16-nucleotide DNA oligomers, and proteins (streptavidin and antibodies) al pico-and femtomolar analyte concentrations. The sensor is also highly effective for detecting single and multilayered molecular assemblies.