A piezoelectric organic surface to control bacterial adhesion and growth

Abstract

All organisms respond to vibration and bacteria are no exception. Previous studies showed that bacteria cells respond to vibrational cues, but the precise mechanisms of adhesion and growth in such conditions are still poorly explored. This work aims to unravel the mechanisms underlying bacterial adhesion to surfaces by investigating how vibrational environments influence bacterial behavior. To answer such questions, substrates based on the piezoelectric polymer Polyvinylidene Fluoride (PVDF) are used. The device in object consists on a glass slide on top of which a flat PVDF layer sandwiched between two gold electrodes is fabricated. Experiments are conducted on E.Coli bacteria expressing mCherry as a fluorescent marker, in a specifically designed chamber that ensures to avoid external perturbations. Vibrational stimuli are applied to the surface via the gold electrodes for different durations using a frequency generator. The substrate is then rinsed and bacteria attached to the surface are observed and quantified using a confocal fluorescent microscope. This project has several applications ranging from the medical field at an industry level to a niche area such as laboratory work related to bacteria. Being able to inhibit bacterial adhesion to surfaces would help preventing infections in humans caused by bacterial biofilm formation on medical instruments and implantable devices; monitoring bacteria growth at the desired speed by simply sweeping the voltage applied to the surface would represent an interesting technique to adopt in laboratories. A flipped approach would bring to think of bacteria as active elements in electro-mechanical sensors.