Plasma micro-nanotextured polymeric micromixer for DNA purification with high efficiency and dynamic range

Area of Science:

• Biotechnology
• Microfluidics
• Analytical Chemistry

Background:

• Integrated Lab-on-chip platforms require efficient nucleic acid purification modules.
• Solid phase extraction is a common method for DNA isolation.
• Microfluidic devices offer miniaturization and enhanced reaction kinetics.

Purpose of the Study:

• To develop and characterize a polymeric microfluidic chip for DNA purification via solid phase extraction.
• To integrate this chip into a Lab-on-chip platform for pathogen detection.
• To assess its performance as a stand-alone DNA purification device.

Main Methods:

• Fabrication of a polymeric microfluidic chip with oxygen plasma micro-nanotextured channels.
• Utilizing carboxyl groups (COOH) on the channel surface for DNA binding with a specific buffer.
• Incorporating an on-chip mixer for efficient sample and buffer mixing under continuous flow.
• DNA elution using water.

Main Results:

• Achieved high DNA recovery efficiency of 96±11%.
• Demonstrated a wide dynamic range for DNA isolation, from 5 to 1.9 × 10^8 Salmonella cells (0.263 fg to 2 × 500 ng).
• Validated chip performance using absorbance measurements, polymerase chain reaction (PCR), and gel electrophoresis.

Conclusions:

• The developed microfluidic chip effectively purifies DNA using solid phase extraction.
• The device shows promise as a module for integrated pathogen detection systems and as a stand-alone purification tool.
• The micro-nanotexturing and buffer system enable efficient DNA binding and elution over a broad concentration range.