Shadow masking for nanomaterial-based biosensors incorporated with a microfluidic device

Area of Science:

• Materials Science
• Biotechnology
• Microfluidics

Background:

• Integrating pre-functionalized biosensors into microfluidic devices is challenging due to O2 plasma treatment damage.
• Irreversible sealing of polydimethylsiloxane (PDMS) channels and biosensor chips requires robust protection methods.

Purpose of the Study:

• To evaluate the effectiveness of a shadow mask in protecting pre-functionalized biosensors during O2 plasma treatment.
• To enable the integration of nanowire biosensors into microfluidic devices for sensitive detection.

Main Methods:

• Pre-functionalization of single nanowire sensors with biomolecules.
• O2 plasma treatment with and without a shadow mask for comparative analysis.
• Detection performance assessment of polypyrrole and polyaniline nanowire biosensors before and after plasma treatment.

Main Results:

• Sensors without a shadow mask experienced irreversible damage (infinite resistance, reduced fluorescence).
• Sensors protected by the shadow mask showed minimal changes in resistance and fluorescence.
• Protected nanowire biosensors maintained good sensitivity, with a slight response reduction post-treatment.

Conclusions:

• Shadow mask is an effective method for protecting pre-functionalized biosensors during microfluidic device fabrication.
• The developed microfluidic biosensor demonstrates high sensitivity for detecting low concentrations of target molecules (e.g., IgE protein).