Spin-Dependent Tunneling Sensors for Vehicle Detection

This project addresses needs for a simple portable microbiological-assay system to rapidly field test water supplies for microbial contaminants and establish safety for human use. The goal is to perfect an analyzer that within hours can determine whetherpotable water samples contain more than one E. coli organism per 100ml. The basis for the analyzer is an innovative oxygen sensor technology that sensitively measures respiratory activity of microorganisms.The research focus is to incorporate the sensor into microbial-filter membranes that will enable waterborne bacteria to be isolated from relatively large volume water samples by filtration. The captured organisms will be cultured briefly in selective-mediato enable proper identification of the target bacteria. The subsequent sensor measures of oxygen consumption will semi-quantitatively resolve the number of microbes that were found in the water.The research efforts include: development of the novel sensor-filter element capable of filtering a large sample of water; development of special assay-vessels for the culture and simultaneous monitoring of the sensor; and instrumentation for conductingthe incubation and reading of the sensor-filter's signal output. It is anticipated that the sensor system will detect the presence and measure metabolic activity of 10-20 organisms within one to two hours.