The detection of Pseudomonas aeruginosa using the quartz crystal microbalance

The development of a piezoelectric immunosensor for the detection of Pseudomonas aeruginosa in milk and dairy samples was undertaken here. This was achieved primarily by optimising the system using. ELISA, investigating capture, competitive and displacement assays. Results from ELISA supplied information on detection limits and linear ranges obtained with each assay. A displacement assay was chosen to be transferred to the piezoelectric system and the reduction in mass on the surface of the crystal due to antigen displacement was measured by recording the frequency changes of the quartz crystal microbalance. The linear range obtained was from 2x10(6) cell/ml to 1x10(8) cell/ml and the limit of detection was 100,000 cells. The system was also tested for cross reactivity with a non-specific antigen, Pseudomonas fluorescens.