Paired bacteria turn chemical detection into an electrical signal a household multimeter can read
Rice University researchers split whole-cell bioelectronic sensing between a 'sender' bacterium that detects a target and a 'receiver' that converts the message into current, and used it to detect metals, small molecules and peptides.
What happened
The team built e-COSENS, an "electroactive co-culture sensing system" made of two bacteria with separate jobs. A sender bacterium produces electron mediators when it meets the substance being measured. A receiver bacterium uses those mediators to generate an electrical signal through extracellular electron transfer.
By swapping the sender and its genetic sensing elements, the researchers detected metals, small molecules and peptides in urban waterways, milk, saliva and microbial communities. They also designed a centimetre-sized device whose output can be read with a household digital multimeter.
Why it matters
Whole-cell bioelectronic sensors suit long-term environmental and health monitoring because they can be built into compact electronics. According to the authors, existing designs are not modular, work in only a few microbial hosts and need specialised instruments to read. Separating detection from signal generation means the electrical half does not have to be re-engineered for every new target.
Caveats
This entry is based on the paper's abstract; the full text was not read. The abstract gives no detection limits, response times or operating lifetimes, so it does not show how the system compares with conventional sensors. It also does not say whether devices were deployed in the field or tested on collected samples.
Synthetic microbial co-cultures for modular bioelectronic sensing in diverse environments
Read at Nature Biotechnology ↗