Label-free and highly sensitive biomolecular detection using SERS and electrokinetic preconcentration

Area of Science:

• Analytical Chemistry
• Biophysics
• Spectroscopy

Background:

• Label-free detection of biomolecules is crucial for various applications.
• Low concentrations of biomolecules present significant detection challenges.
• Existing methods often require complex labeling or preconcentration steps.

Purpose of the Study:

• To develop a highly sensitive, label-free method for biomolecule detection.
• To enhance biomolecular signals using electrokinetic preconcentration combined with SERS.
• To achieve significant signal amplification for trace analyte detection.

Main Methods:

• Integration of surface-enhanced Raman scattering (SERS) spectroscopy with electrophoresis.
• Application of a constant electric field to preconcentrate charged biomolecules onto a SERS substrate.
• Utilizing the SERS substrate as an electrode for electrokinetic concentration.

Main Results:

• Achieved an 8-order of magnitude sensitivity improvement for adenine detection (10 fM to 1 microM).
• Demonstrated signal amplification to levels comparable to non-preconcentrated higher concentrations.
• Observed a 51-fold signal intensity increase under optimized electric field (-0.6 V cm(-1)) and time (25 min).

Conclusions:

• The combined SERS and electrophoresis technique offers a powerful tool for sensitive biomolecule detection.
• This method enables label-free, target-specific, and highly sensitive monitoring.
• The approach has potential for developing advanced biosensing and diagnostic applications.