Chiral Au@Ag Core–Shell Nanoparticles for Enantioselective SERS Detection of Bio-Relevant Chiral Molecules

High Resolution Image Download MS PowerPoint Slide Chiral Au@Ag core–shell nanoparticles were synthesized by asymmetric Ag deposition on premade chiral Au nanorods and employed for enantioselective surface-enhanced Raman scattering (SERS) of bio-relevant chiral molecules. Electron tomography revealed nanoscale asymmetry arising during Ag shell growth, while circular dichroism spectroscopy and electromagnetic simulations confirmed strong optical activity. Differential SERS under circularly polarized light (CPL-SERS) demonstrated distinct spectral responses for L - and D -3,4-dihydroxyphenylalanine ( L / D -DOPA), achieving enantiomeric discrimination exceeding 95% accuracy through principal-component linear-discriminant analysis. The combination of experimental and computational results reveals a direct structure-chirality-sensing correlation and establishes Au@Ag core–shell nanostructures as versatile platforms for ultrasensitive chiral detection.