Wireless Potentiometric Monitoring of Microbial Biofilm Formation: In Vitro and Ex Vivo Studies of Gram-Positive and Gram-Negative Bacteria

Abstract

A wireless potentiometric sensor offers a robust platform for detecting microbial growth, which is crucial for managing infected wounds that can lead to serious complications such as tissue spread, systemic infection, or sepsis, potentially resulting in life-threatening conditions. Herein, a solid-state potentiometric working/reference electrode system with a Bluetooth-enabled system on a chip, supporting continuous wireless monitoring of microbial growth is shown. The sensor monitors open circuit potentials (OCPs) in culture media, which significantly decrease due to bacterial growth after inoculation with Gram-positive Staphylococcus aureus, Gram-negative Pseudomonas aeruginosa, and Escherichia coli. Notably, Staphylococcus aureus demonstrates lower electrogenic activity compared with the Gram-negative bacteria, likely owing to its reduced viability. Following thorough in vitro testing, the sensor is also evaluated ex vivo. Stable connections between the sensor and a smartphone receiver ensure reliable data collection and processing, facilitating remote monitoring. A slight decrease in OCP is observed in rat wounds inoculated with Staphylococcus aureus and significant decrease with Pseudomonas aeruginosa. Incorporation of the wireless sensing module for continuous measurement and data collection can greatly enhance early detection capabilities regarding bacterial infections in wounds. This setup offers a convenient and effective method for point-of-care sensing, significantly advancing the management and treatment of wound infections.