A microfluidics assisted porous silicon array for optical label-free biochemical sensing

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Label-free detection of DNA-DNA interactions is crucial for diagnostics.
• Existing methods often require significant reagent consumption and time.
• Integrated microfluidic and photonic crystal systems offer potential for enhanced biosensing.

Purpose of the Study:

• To develop and validate a porous silicon (PSi) microarray integrated with microfluidics for optical monitoring of label-free DNA-DNA interactions.
• To demonstrate reduced reagent consumption and incubation time compared to non-integrated devices.
• To establish a numerical model for device optimization.

Main Methods:

• Fabrication of a 4x4 PSi one-dimensional photonic crystal microarray.
• Integration with a polydimethylsiloxane (PDMS) microfluidic channel circuit.
• Functionalization of PSi elements with single-stranded DNA.
• Monitoring of functionalization and DNA interaction using spectroscopic reflectometry.
• Theoretical calculations using finite element method.

Main Results:

• Successful integration of PSi microarray with microfluidics for DNA sensing.
• Significant reduction in biologicals, chemicals, and incubation time.
• Experimental results show good agreement with theoretical calculations.
• Spectroscopic reflectometry effectively monitored DNA probe-target interactions on individual PSi elements.

Conclusions:

• The integrated PSi microarray and microfluidic system is a viable platform for label-free DNA-DNA interaction monitoring.
• The developed numerical model aids in optimizing the device's performance.
• This approach offers a more efficient and cost-effective method for genetic analysis and diagnostics.