Alternative cDEP Design to Facilitate Cell Isolation for Identification by Raman Spectroscopy

Area of Science:

• Biophysics
• Microfluidics
• Spectroscopy

Background:

• Dielectrophoresis (DEP) is a label-free technique for manipulating particles using non-uniform electric fields.
• Contactless dielectrophoresis (cDEP) offers advantages over traditional DEP by preventing electrode fouling and electrolysis.
• Existing cDEP devices fabricated with polydimethylsiloxane (PDMS) face limitations in fabrication, reusability, and operating voltage due to dielectric breakdown.

Purpose of the Study:

• To develop an alternative fabrication method for cDEP devices using fused silica.
• To overcome the limitations of PDMS-based cDEP devices, including fabrication challenges and restricted operating parameters.
• To enable higher operating voltages and integrate Raman spectroscopy for simultaneous particle manipulation and identification.

Main Methods:

• Fabrication of cDEP channels using fused silica instead of PDMS.
• Implementation of contactless dielectrophoresis for particle manipulation.
• Integration of Raman spectroscopy for in-situ analysis of trapped particles.

Main Results:

• Successfully fabricated a cDEP device with channels made of fused silica.
• Demonstrated the ability to trap 3.3 μm polystyrene spheres using the fused silica cDEP device.
• Achieved higher operating voltages compared to conventional PDMS-based devices.

Conclusions:

• Fused silica is a viable material for fabricating robust cDEP devices.
• The developed cDEP device allows for higher operating voltages and improved replication.
• This technology holds potential for isolating and identifying biological samples on a single, integrated device using Raman spectroscopy.