A progress report on the LDRD project entitled {open_quotes}Microelectronic silicon-based chemical sensors: Ultradetection of high value molecules{close_quotes}

This work addresses a new kind of silicon based chemical sensor that combines the reliability and stability of silicon microelectronic field effect devices with the highly selective and sensitive immunoassay. The sensor works on the principle that thin SiN layers on lightly doped Si can detect pH changes rapidly and reversibly. The pH changes affect the surface potential, and that can be quickly determined by pulsed photovoltage measurements. To detect other species, chemically sensitive films were deposited on the SiN where the presence of the chosen analyte results in pH changes through chemical reactions. A invention of a cell sorting device based on these principles is also described. A new method of immobilizing enzymes using Sandia`s sol-gel glasses is documented and biosensors based on the silicon wafer and an amperometric technique are detailed