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Microfluidic Picoliter Bioreactor for Microbial Single-cell Analysis: Fabrication, System Setup, and Operation
Published on: December 6, 2013
Microfluidic conductimetric bioreactor
Warakorn Limbut1, Suchera Loyprasert, Chongdee Thammakhet
1Biophysics Research Unit of Biosensors and Biocurrents, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
Biosensors & Bioelectronics
|February 10, 2007
Summary
A novel microfluidic bioreactor uses immobilized enzymes for conductimetric detection. This system offers stable and repeatable urea detection, validated with human serum samples, demonstrating its practical application in diagnostics.
Area of Science:
- Biotechnology
- Analytical Chemistry
- Microfluidics
Background:
- Enzyme immobilization is crucial for developing stable biosensors.
- Microfluidic systems offer advantages in sample handling and reaction control.
- Conductimetric detection provides a sensitive method for monitoring biochemical reactions.
Purpose of the Study:
- To develop and characterize a microfluidic conductimetric bioreactor for analyte detection.
- To immobilize urease enzyme onto a poly-dimethylsiloxane (PDMS) surface for urea sensing.
- To evaluate the performance and reusability of the developed biosensor system.
Main Methods:
- Enzyme immobilization via covalent binding on a PDMS microfluidic chip.
- Conductimetric detection using gold electrodes and a custom transducer.
- Urea determination using the urea-urease enzyme system.
- Validation with human serum samples using the Berthelot reaction for comparison.
Main Results:
- Achieved a urea detection limit of 0.09 mM with linearity from 0.1-10 mM (r=0.9944).
- Demonstrated good enzyme stability (>30 days) and repeatability (R.S.D. < 2.3%).
- Showed good agreement with the Berthelot reaction for human serum urea concentration determination (P<0.05).
Conclusions:
- The developed microfluidic conductimetric bioreactor is a stable, repeatable, and sensitive platform for urea detection.
- The reusability of the microfluidic chip after enzyme removal enhances its economic viability.
- This system shows potential for practical applications in clinical diagnostics and biochemical analysis.
