Magnesium Zinc Oxide Nanostructure-Modified Multifunctional Sensors for Full-Scale Dynamic Monitoring of Pseudomonas aeruginosa Biofilm Formation

Abstract

We demonstrate magnesium zinc oxide nanostructure (MZOnano) modified multifunctional devices for the full-scale dynamic monitoring of Pseudomonas aeruginosa (P. aeruginosa) biofilm formation: the dual-gate thin film transistor (DGTFT) as an electrical sensor for early stage detection and the quartz crystal microbalance (QCM) as an acoustic sensor for long-term monitoring. The sensing surfaces of both devices were modified with MZOnano to enhance their sensitivity and biocompatibility. P. aeruginosa bacteria were cultured in vitro on both sensing surfaces. The early stage detection is realized by sensing the charge transfer from cell membrane to the MZOnano during bacterial adhesion using the DGTFT biosensor while the monitoring of the long-term evolution is achieved through the sensing of mass loading and viscoelastic transition during biofilm development using the MZOnano QCM. The drain current of DGTFT starts to change at the beginning of the test and levels off after ∼6.5 h of bacterial inoculation, whereas the signals of MZOnano QCM become detectable after ∼5 h and then lasts for 24 h. The full-scale process of biofilm development covering from bacterial adhesion to maturation is thus dynamically monitored using this MZOnano modified multifunctional sensing technology.