A Novel Mobile Monitoring System for Fast and Automated Bacteria Detection in Water

Standard detection methods for viable bacteria in potable water are time consuming due to a required cultivation step. Fast and automated detection of water borne microorganisms with high sensitivity and selectivity is still a challenge. We report on a novel biosensor using micromechanical filters with nano sized pores to capture and enrich bacteria on the filter surface and subsequent detection using fluorescent probes. The whole process is fully automated by integrating the sieves into a fluidic system together with a high performance fluorescence detector. The results show the effective retention of bacteria on the filter surface, which are then accessible for different staining procedures. As an example, we use special fluorescent dyes that bind to or intercalate in the DNA molecules of the bacteria. After detection, the microfilters undergo cleaning and conditioning steps to be ready for the next measurement.