Microbial Fuel Cell Biosensor with Capillary Carbon Source Delivery for Real-Time Toxicity Detection.

Area of Science:

• Environmental Science
• Electrochemistry
• Microbiology

Background:

• Microbial fuel cell (MFC) biosensors struggle with reliability in low or fluctuating organic matter conditions.
• Carbon-depleted environments, such as potable water, pose challenges for existing MFC biosensor applications.

Purpose of the Study:

• To overcome limitations of MFC biosensors in carbon-depleted environments.
• To develop a capillary action-aided carbon source delivery system for MFC biosensors.
• To enable real-time toxicant detection in environments with low organic matter.

Main Methods:

• Evaluated different thread materials (silk, nylon, cotton, polyester) for capillary carbon source delivery.
• Incorporated a silk thread-based acetate delivery system into an MFC biosensor.
• Tested the MFC biosensor's ability to detect toxicant spikes (chlorine, formaldehyde, mercury, microcystins) in tap water.
• Utilized 16S rRNA gene sequencing to analyze microbial community composition.

Main Results:

• Silk thread demonstrated optimal performance for passive delivery of acetate solution.
• The developed MFC biosensor successfully detected toxicant spikes in tap water (organic matter 56 ± 15 mg L^-1).
• Key microbial genera identified include Desulfatirhabdium, Pelobacter, and Geobacter.

Conclusions:

• Capillary action-aided carbon source delivery enhances MFC biosensor performance in carbon-depleted settings.
• The proposed system enables real-time toxicant monitoring in environments previously unsuitable for MFC biosensors.
• This approach offers a viable solution for water quality monitoring.