A bacterial biofilm Surface Acoustic Wave sensor for real time biofilm growth monitoring

We present the design, fabrication and the first successful demonstration of a bacterial biofilm Surface Acoustic Wave (SAW) sensor. Bacterial biofilms cause severe infections, and are often difficult to remove without invasive surgery. Hence, their detection at an early stage is critical for effective treatment. The detection of biofilm growth is achieved using a high quality zinc oxide (ZnO) piezoelectric thin film which is grown by pulsed laser deposition (PLD). The detection limit of the SAW sensor is approximately 5.3 pico-grams (10^-12 g). The resonant frequency shift of the SAW sensor over the biofilm growth period corresponds to in-vitro biofilm growth, demonstrating the first application of a SAW sensor toward real time biofilm sensing. The sensor is biocompatible and the operation frequency is designed to meet the regulations set forth by the Federal Communication Commission (FCC) for implantable applications.