Biofilms are one of the most resilient and adaptive strategies that microorganisms use to survive under difficult conditions. Their ability to form protective matrices makes them a critical threat in healthcare, as they often cause persistent infections. While established techniques exist to characterize biofilms, they face several challenges, primarily due to labor intensity, time consumption, complex sample preparation, and the high cost of imaging equipment. In developing countries, costs are particularly high due to limited detection infrastructure, highlighting the need for a complementary characterization technique that enables standardized, cheap, and rapid characterization of biofilm composition and metabolic activity.

In this study, we developed and optimized a short-term potentiometric method to investigate early biofilm formation by measuring in real-time the charge and discharge of bacterial membrane potentials. When grown on a polarized surface, the bacterial attachment generates microscale currents that can be correlated to cell concentration, nutrients, and environmental conditions, among other factors. By analyzing the bacterial current output, we were able to detect early biofilm formation within 4–6 hours, a significant improvement over conventional methods, which typically require 18–24 hours and at lower costs (~1 USD per sample). The results obtained were validated against a control experiment (open-circuit potentiometry) with established biofilm characterization methods to verify the non-destructive capability of the developed technique.

The proposed technique can be effectively used to detect early biofilms without the need for redox mediators, thereby extending its application to the bioelectrochemical analysis of microorganisms of clinical importance, which are often weak electricigens.