Reaction-Modulated Surface-Enhanced Raman Scattering Strategy for Stereoselective Differentiation and Identification...

Area of Science:

• Nanomaterials Science
• Analytical Chemistry
• Spectroscopy

Background:

• Distinguishing enantiomers in racemates is challenging due to their similar physicochemical properties.
• Surface-enhanced Raman scattering (SERS) offers potential for molecular fingerprinting but struggles with enantiomeric discrimination.
• Nucleophilic addition reaction (NAR) exhibits enantioselective behavior towards amino acids.

Purpose of the Study:

• To develop a robust SERS method for discriminating between d- and l-valine.
• To synergize asymmetric gold nanorods-embedded ZIF-8 nanoparticles (AGNZ) with NAR for enhanced enantioselective sensing.
• To establish a universal strategy for recognizing various amino acid enantiomers and quantifying racemic ratios.

Main Methods:

• Fabrication of asymmetric gold nanorods-embedded ZIF-8 nanoparticles (AGNZ).
• Application of nucleophilic addition reaction (NAR) to induce stereoselective interactions.
• Utilizing SERS spectroscopy combined with chemometric analysis for molecular fingerprinting and quantification.
• Investigating the role of AGNZ's interfacial cavities and 3D hotspots in enantiospecific adsorption.

Main Results:

• Achieved highly effective and robust SERS discrimination of d- and l-valine.
• Demonstrated that AGNZ provides confined asymmetrical surroundings triggering enantiospecific adsorption.
• Showcased NAR's role in bringing racemates to the AGNZ interface for enhanced interaction.
• Validated the universality of the strategy for other amino acid enantiomers.

Conclusions:

• The synergistic combination of AGNZ and NAR provides a significant advancement in SERS-based racemate discrimination.
• This strategy overcomes limitations of traditional methods by leveraging stereoselective molecular interactions.
• The developed approach offers a powerful paradigm shift for sensitive and accurate enantiomeric analysis.