A Single-Layer PDMS Chamber for On-Chip Bacteria Culture

Area of Science:

• Biotechnology
• Microfluidics
• Environmental Science

Background:

• On-chip cell culture devices are crucial for biological research.
• Existing designs often use complex multi-layer microfluidic valves made of polydimethylsiloxane (PDMS).
• These complex designs present challenges in fabrication and operation.

Purpose of the Study:

• To develop a simplified single-layer microfluidic valve for on-chip bacterial culture.
• To enable long-term culture of E. coli for biosensing applications.
• To detect heavy metal ions using a genetically modified E. coli whole-cell biosensor.

Main Methods:

• Introduction of single-layer PDMS microfluidic valves in an on-chip culture chamber design.
• Development of a (semi-)always-closed microfluidic valve for continuous medium flow.
• Application of the device for whole-cell detection of heavy metal ions using genetically modified E. coli.

Main Results:

• The developed growth chamber successfully cultured E. coli over an extended period.
• The platform achieved a limit-of-detection (LoD) of 44.8 parts per billion (ppb) for Cadmium ions.
• The device demonstrated effective whole-cell detection of heavy metal ions.

Conclusions:

• Single-layer PDMS microfluidic valves offer a simplified approach to on-chip bacterial culture.
• The developed microfluidic device is suitable for long-term bacterial cultivation and heavy metal ion detection.
• This platform provides a sensitive and efficient method for environmental monitoring.