Gold nanoparticles with helical surface structure transformed from chiral molecules for SERS-active substrates...

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Surface-enhanced Raman scattering (SERS) requires highly sensitive SERS-active materials.
• Developing efficient SERS substrates is crucial for expanding Raman spectroscopy applications.

Purpose of the Study:

• To propose and characterize a novel SERS substrate using helical gold nanoparticles synthesized with L-glutathione (L-GSH).
• To evaluate the SERS performance and application potential of the fabricated nanostructures.

Main Methods:

• Directed synthesis of helical gold nanoparticles using L-glutathione.
• Characterization of nanostructure morphology and surface properties.
• Experimental measurements and finite difference time domain (FDTD) simulations to understand enhancement mechanisms.
• Application testing for thiram detection on pear surfaces.

Main Results:

• Helical gold nanoparticles exhibited a large specific surface area and unique electronic properties.
• Achieved an impressive average enhancement factor (EF) of 2.95 × 10^5 under off-resonant conditions.
• Successfully detected thiram on pear with a limit of detection (LOD) of 0.62 mg/kg and R^2 of 0.9772.

Conclusions:

• The proposed helical gold nanoparticle SERS substrates demonstrate exceptional sensitivity and potential for practical applications.
• Chiral molecules like amino acids and peptides can be utilized in fabricating advanced SERS-active materials.
• This work opens avenues for sensitive detection of analytes in complex matrices.