Surface-enhanced Raman scattering of DNA bases using frozen silver nanoparticle dispersion as a platform

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Nanotechnology

Background:

• Raman spectroscopy offers molecular characterization but suffers from low sensitivity.
• Surface-enhanced Raman scattering (SERS) improves sensitivity but faces challenges in substrate preparation, sensitivity control, and reproducibility.
• Existing SERS methods require complex procedures and lack consistent results.

Purpose of the Study:

• To develop a simple, sensitive, and reproducible SERS platform.
• To overcome limitations of current SERS substrate preparation and measurement techniques.
• To utilize freezing as a method for enhancing SERS signals using DNA bases as model analytes.

Main Methods:

• Proposed a novel SERS method employing simple freezing of samples.
• Utilized silver nanoparticles (AgNPs) as SERS substrates.
• Investigated the effect of freezing on analyte and AgNP concentration and aggregation.

Main Results:

• Freezing concentrates solutes and AgNPs, promoting nanoparticle aggregation and enhancing SERS signals.
• Achieved up to 5000-fold enhancement in SERS signal intensity.
• Demonstrated simultaneous detection of four DNA bases, reducing signal variations and enabling reliable concentration ratio determination.

Conclusions:

• Freezing provides an efficient and simple method for preparing SERS platforms.
• The proposed technique significantly enhances SERS sensitivity and reproducibility.
• This approach offers a reliable platform for sensitive molecular detection and analysis.