Detection of Ralstonia pickettii bacteria in m9 medium using polymer nanocomposite sensors

Detection of bacteria such as Ralstonia pickettii in high purity water (HPW) has gained increasing interest for researchers. Contamination problems in HPW in both pharmaceutical and semiconductor applications can lead to a reduction in performance and inefficiency in production chains leading to huge expense. Real time detection of these bacteria in HPW prior to use can allow corrective action to be taken sooner, by reallocating the water for repurification or utilization elsewhere thereby reducing industrial costs The aim of this study was to evaluate the responses of polymer nanocomposite sensors to increasing concentrations of Ralstonia pickettii bacteria. M9 minimal growth medium was used to grow the bacteria and three different concentrations were prepared by taking samples after 2 hours, 4 hours and 6 hours of growth. The sensors showed large sensitivity to each concentration of bacteria and produced a decrease in response over the growth cycle of the bacteria. These sensors demonstrated the ability to detect early stage actively growing cells in real time, which is of large benefit to HPW applications. This work has shown that these sensors can be used to detect both lag phase and late exponential and stationary phase growing cells in a minimal nutrient environment.