A highly sensitive surface-enhanced Raman scattering substrate prepared on a hydrophobic surface using controlled...

Area of Science:

• Materials Science
• Analytical Chemistry
• Spectroscopy

Background:

• Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical technique.
• Developing sensitive and easily fabricated SERS substrates is crucial for widespread application.
• Existing methods often involve complex fabrication processes or super-hydrophobic surfaces.

Purpose of the Study:

• To fabricate a simple and easily manufacturable SERS substrate on a hydrophobic surface.
• To investigate the effect of evaporation rate on substrate performance.
• To compare the sensitivity of different SERS substrates for molecule detection.

Main Methods:

• Fabrication of SERS substrates by controlled evaporation (slow and fast) of silver nanoparticle suspension on a hydrophobic surface.
• Characterization of dried spot morphology and coffee stain effect.
• SERS measurements using a lab-built setup to detect rhodamine 6G molecules.

Main Results:

• Slow evaporation ('s_evp') resulted in smaller dried spot sizes and minimized the coffee stain effect compared to fast evaporation ('f_evp').
• The 's_evp' substrate demonstrated superior enrichment of the analyte spot.
• Detection of rhodamine 6G down to 2.5 × 10^-12 M was achieved with the 's_evp' substrate, significantly lower than the 2.5 × 10^-10 M limit for 'f_evp'.

Conclusions:

• The proposed 's_evp' SERS substrate fabricated via slow evaporation is simple, easy to use, and highly sensitive.
• This method provides a more accessible alternative to super-hydrophobic SERS substrates.
• The developed substrate shows great potential for sensitive chemical and biological detection.