Evaluation of Pseudomonas aeruginosa biofilm formation using Quartz Tuning Forks as impedance sensors

The shape of metallisation on Quartz Tuning Forks (QTFs) allowed to use them as impedance sensors for monitoring biofilm formation of Pseudomonas aeruginosa strains. Electrical equivalent circuits modelling was used. It allowed to detect which electrical properties of the sensor change with biofilm formation. Characteristic frequencies of 20 Hz and 1 MHz were found as suitable for the simple detection of biofilm state. Resistance measured at 1 MHz allowed to detect the changes in media conductivity caused by bacterial culture growth. It was in accordance with the results obtained using another methods. In addition, the conductance at 20 Hz was suitable for detection of biofilm destruction caused by the lack of nutrients.