Monitoring biofilm growth and dispersal in real-time with impedance biosensors.

Microbial biofilm contamination is a widespread problem that requires precise and prompt detection techniques to effectively control its growth. Microfabricated electrochemical impedance spectroscopy (EIS) biosensors offer promise as a tool for early biofilm detection and monitoring of elimination. This study utilized a custom flow cell system with integrated sensors to make real-time impedance measurements of biofilm growth under flow conditions, which were correlated with confocal laser scanning microscopy (CLSM) imaging. Biofilm growth on EIS biosensors in basic aqueous growth media (tryptic soy broth; TSB) and an oil-water emulsion (metalworking fluid; MWF) attenuated in a sigmoidal decay pattern, which lead to an ∼22 to 25% decrease in impedance after 24 hours. Subsequent treatment of established biofilms increased impedance by ∼14% and ∼41% in TSB and MWF, respectively. In the presence of Furanone C-30, a quorum sensing inhibitor (QSI), impedance remained unchanged from the initial time point for 18 hours in TSB and 72 hours in MWF. Biofilm changes enumerated from CLSM imaging corroborated impedance measurements, with treatment significantly reducing biofilm. Overall, these results support the application of microfabricated EIS biosensors for evaluating the growth and dispersal of biofilm in situ and demonstrate potential for use in industrial settings.