Porous carbon nanowire array for surface-enhanced Raman spectroscopy

Area of Science:

• Nanomaterials Science
• Spectroscopy
• Biomedical Engineering

Background:

• Surface-enhanced Raman spectroscopy (SERS) offers high sensitivity for vibrational spectroscopy by utilizing localized surface plasmon resonance (LSPR) on metal substrates.
• Traditional SERS substrates face challenges in reproducibility, uniformity, biocompatibility, and durability due to hot spots, photothermal effects, and oxidation, limiting biomedical applications.

Purpose of the Study:

• To design, fabricate, and utilize a metal-free, topologically tailored nanostructure as a SERS substrate.
• To overcome the limitations of conventional metal-based SERS substrates for enhanced biomedical sensing.

Main Methods:

• Fabrication of a metal-free SERS substrate using porous carbon nanowires in an array.
• Characterization of the nanostructure's surface properties and plasmonic behavior (or lack thereof).
• Evaluation of the substrate's performance in terms of signal enhancement, reproducibility, durability, and biocompatibility.

Main Results:

• Achieved high signal enhancement (~10^6) attributed to broadband charge-transfer resonance, not LSPR.
• Demonstrated extraordinary reproducibility due to the absence of plasmonic hot spots.
• Exhibited high durability, free from oxidation issues common in metal substrates.
• Showcased high compatibility with biomolecules, including fluorescence quenching capabilities.

Conclusions:

• The developed metal-free porous carbon nanowire array serves as a robust and reliable SERS substrate.
• This novel substrate overcomes key limitations of traditional SERS, paving the way for advanced biomedical sensing.
• The design offers a promising alternative for sensitive, reproducible, and durable molecular detection in biological systems.