Surface-Enhanced Raman Spectroscopic Probing in Digital Microfluidics through a Microspray Hole

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Microfluidics

Background:

• Surface-enhanced Raman spectroscopy (SERS) offers high sensitivity for molecular detection.
• Digital microfluidics (DMF) enables precise control of small fluid volumes.
• Integrating SERS with DMF presents challenges in sample transfer and substrate compatibility.

Purpose of the Study:

• To develop a novel SERS detection approach within a digital microfluidics (DMF) platform.
• To enable efficient sample transfer from DMF to an external SERS substrate.
• To demonstrate the utility of this integrated system for analyte detection and reaction monitoring.

Main Methods:

• Development of a microspray hole (μSH) for electrostatic spray (ESTAS) assisted sample transfer.
• Design and characterization of a new ESTAS-compatible stationary SERS substrate.
• Proof-of-concept detection of various analyte molecules using the integrated DMF-SERS system.

Main Results:

• Successful implementation of sample transfer from DMF to an external SERS substrate via ESTAS.
• Achieved micro-molar detection limits for various analyte molecules.
• Demonstrated vibrational spectroscopic analysis of an organic reaction occurring within the DMF device.

Conclusions:

• The novel DMF-SERS approach facilitates sensitive and reproducible molecular detection.
• The integrated system provides a versatile platform for chemical analysis and reaction studies.
• This technique expands the capabilities of microfluidic devices for spectroscopic applications.