E. coli Engineered Into a Self-Powered Mercury Sensor
Why in the news
Scientists have turned genetically engineered E. coli into a whole-cell biosensor that detects mercury and produces an electrical output. The work comes from Imperial College London and Zhejiang University.
Key facts
- Trigger: mercury in water activates the MerR protein, which acts as a molecular switch.
- Response: the bacteria make phenazines, molecules that interact with an electrode.
- Signal: the resulting current grows stronger as mercury concentration rises.
- Goal: cheap, self-powered, programmable biosensors.
| Component | Role |
|---|---|
| E. coli (engineered) | Living sensor |
| MerR protein | Detects mercury and acts as a switch |
| Phenazines | Carry electrons to the electrode |
| Electrode | Reads the current |
About whole-cell biosensors
Unlike enzyme-based sensors, which are fragile and costly, living microbes are more durable and cheaper, and can regenerate themselves. Possible uses include detecting toxins in drinking water, tracking aquatic pollution, early warnings of contamination and portable field devices. The work also advances programmable bioelectronics.
Exam angle
- Link it with synthetic biology and heavy-metal pollution.
- Remember the sensing chain: mercury, MerR, phenazines, current.
- Mercury is a toxic heavy metal in water pollution questions.