Bioelectronic sensor uses living bacteria

March 14, 2026

Researchers have unveiled an innovative bioelectronic sensor powered by living bacteria that produces measurable electrical signals when exposed to targeted chemical substances. This breakthrough in microbial bioelectronics opens the door to durable, self-sustaining environmental sensors for applications in wastewater management, food safety testing, and industrial process monitoring.

Developed by scientists at Rice University, the cutting-edge device leverages naturally electroactive bacteria. These microorganisms generate electrical currents when they encounter specific chemicals, known as analytes, enabling real-time biological detection through electronic readouts.

Why microbial bioelectronic sensors matter

Microbial biosensors have gained significant attention due to their unique advantages:

• Multifunctionality – Bacteria can detect, adapt, and respond to multiple chemical signals.

• Resilience – Many strains survive extreme or contaminated environments.

• Self-regeneration – Living cells can reproduce, offering long-term operational stability.

However, integrating living microbes into electronic systems has historically posed major challenges. In liquid environments, electron-shuttling molecules—called mediators—often diffuse away from the electrode surface. Additionally, some mediators are toxic, limiting their commercial and environmental applications.

A biohybrid solution: hydrogel-based bacterial containment

To overcome these obstacles, researchers engineered a biohybrid hydrogel material that securely houses bacteria while maintaining a stable electrical interface with an electrode.

Hydrogel Traps Active Bacteria Near the Electrode

The team developed a soft hydrogel composed of chitosan, a biodegradable polymer derived from crustacean shells. This hydrogel functions as a semi-permeable matrix:

• It keeps bacteria immobilized close to the electrode surface

• It allows liquids containing analytes to pass through freely

• It creates a stable microenvironment for long-term sensing

According to study co-author Rafael Verduzco, chitosan acts like a protective shell, preventing bacteria from escaping while preserving their biological activity.

To further enhance performance, the researchers chemically modified the chitosan polymer to anchor redox mediators—specialized molecules responsible for transferring electrons from bacteria to the electrode. These modifications ensure consistent and efficient electrical signal transmission.

Redox-active polymer enables signal transmission

The key technological innovation is the integration of a redox-active polymer, capable of accepting electrons from bacterial cells and relaying them directly to the electrode. This design eliminates the instability problems seen in earlier microbial sensors and significantly improves signal reliability.

Real-world application: detecting sakacin P in milk

To validate the system, researchers built a functional biosensor capable of detecting sakacin P, an antimicrobial peptide sometimes used as a natural food preservative.

The team engineered a strain of Lactiplantibacillus plantarum (formerly known as L. plantarum), a probiotic bacterium commonly found in fermented dairy products. When exposed to sakacin P, the modified bacteria generate a small but measurable electrical current.

Embedded within the chitosan hydrogel and connected to an electrode, the bacteria successfully detected sakacin P in milk samples. Within just a few hours, the system produced a clear electrical signal—demonstrating rapid, real-time food safety monitoring potential.

Doctoral researcher Xinyuan Zuo, first author of the study, explained that incorporating a redox-active polymer solved two major problems at once: stabilizing mediator molecules and efficiently transmitting bacterial electrical signals to the electrode.

Future of living bioelectronic devices

Because the hydrogel is composed of renewable, food-safe materials and utilizes bacteria already common in food systems, the technology has broad commercial and environmental potential. Applications may include:

• Wastewater contamination monitoring

• Food quality and spoilage detection

• Industrial bioprocess monitoring

• Chemical production control

• Isolation or neutralization of hazardous compounds

Many bacterial species are naturally electroactive, meaning they can transfer electrons outside their cells. This positions microbial bioelectronic sensors as a scalable platform for next-generation sustainable sensing technologies.

The newly developed hydrogel framework creates a stable electronic communication pathway between living bacteria and electronic devices—paving the way for long-lasting, self-powered, and environmentally friendly bioelectronic systems.