Multifunctional optofluidic lab-on-chip platform for Raman and fluorescence spectroscopic microfluidic analysis

Area of Science:

• Optofluidics
• Spectroscopy
• Lab-on-a-chip technology

Background:

• Traditional spectroscopic analysis often requires large sample volumes and complex instrumentation.
• Existing lab-on-a-chip devices may face challenges with alignment and background noise.
• There is a need for sensitive, portable, and cost-effective analytical platforms.

Purpose of the Study:

• To report a multifunctional lab-on-a-chip platform for spectroscopic analysis of liquid samples.
• To demonstrate the capabilities of an optofluidic jet waveguide for enhanced signal detection.
• To evaluate the platform's performance in fluorescence and Raman spectroscopy.

Main Methods:

• Utilized a micro-jet waveguide (150 μm diameter) for total internal reflection-based optofluidic detection.
• Integrated a recirculation system to minimize sample volume requirements.
• Performed multiwavelength fluorescence spectroscopy on eosin Y and riboflavin.
• Conducted Raman spectroscopy on water-ethanol solutions.

Main Results:

• Achieved a limit of detection of 33 pM for eosin Y fluorescence.
• Demonstrated a limit of detection of 0.18% for water-ethanol mixtures using Raman spectroscopy.
• Detected riboflavin at 560 pM (0.21 ng L⁻¹) via fluorescence.
• Observed performance comparable to or exceeding high-end benchtop equipment.

Conclusions:

• The optofluidic jet waveguide platform offers an alignment-free, highly efficient spectroscopic detection scheme.
• The device enables sensitive analysis with minimal sample volume, suitable for portable applications.
• This technology holds promise for high-sensitivity environmental and biochemical sensing.