Wavelength-Dependent Differential Amplification of Raman Scattering by Chiral Gold Nanorods for Multiplexed Encoding

This record contains the supporting research data for the publication “Wavelength-Dependent Differential Amplification of Raman Scattering by Chiral Gold Nanorods for Multiplexed Encoding” by Serrano-Freijeiro et al., Advanced Functional Materials (2025), DOI: 10.1002/adfm.202507076. Abstract (reproduced from the original publication): The application of wavelength-dependent differential circularly polarized light-induced surface-enhanced Raman scattering (CPL-SERS) is reported for codification and encryption, using colloidal chiral plasmonic nanoparticles. This study demonstrates that intrinsically chiral Au nanorods (c-AuNRs) encoded with achiral Raman reporters display unique optical activity. Right-handed and left-handed c-AuNRs show positive or negative CPL-SERS depending on the illumination wavelength (633 and 785 nm in this case), in correlation with their respective circular dichroism (CD) spectra. This effect enables c-AuNR enantiomeric differentiation through evaluation of the CPL-SERS response for each excitation wavelength. To showcase the potential of this approach, four encoded c-AuNR dispersions were prepared, each with distinct handedness and Raman reporter combinations, and used to encode a four-letter message on paper, which can be selectively decoded through CPL-SERS, even when using only two Raman reporters. By switching between excitation wavelengths of 633 and 785 nm, inverted CPL-SERS signals were recorded, therefore enhancing the versatility of the coding. The integration of chiral plasmonic nanoparticles and CPL-SERS represents a highly tunable platform for advanced sensing, encryption, and codification, thereby expanding the functionality of plasmonic nanostructures in optical technologies.