講演情報
[9a-PA4-25]Time-Dependent Interaction between [AuCl4]- and Cysteine for the Electrochemical Synthesis of Chiral Plasmonic Gold Nanostructures for Chiral Sensing by SERS
〇(B)Tianji Zhang1, Junhe Wang1, Yuta Shiga1, Olga Guselnikova2, Takuya Nakanishi1, Yusuke Yamauchi2,3,4, Toru Asahi1, Kenta Nakagawa1 (1.Waseda Univ., 2.NIMS, 3.Nagoya Univ., 4.Univ. of Queensland)
キーワード：
chirality、SERS、sensing
Chiral plasmonic gold nanostructures are platforms with high potential for chiral molecular sensing because of their chiroptical properties and plasmonic enhancement effect. The localized surface plasmon resonance of these nanostructures that can amplify weak chiroptical responses through enhanced electromagnetic fields and light-matter interaction. When combined with surface-enhanced Raman scattering (SERS), they provide complementary molecular vibrational information, offering new opportunities for the sensitive detection and discrimination of chiral molecules. However, the reproducible synthesis of chiral gold nanostructures by electrochemical methods requires a deeper understanding of the chemical state of gold–chiral additive complexes in the electrolyte before electrodeposition. In this study, we focused on the time-dependent interaction between [AuCl4]- and cysteine and investigated how this solution reaction affects the formation of chiral gold nanostructures.
Chiral gold nanostructures were deposited on the coral-like gold substrate from an electrolyte containing HAuCl4, KCl, and either L- or D-cysteine, based on a one-step electrodeposition method for chiral plasmonic gold nanostructures. The obtained film exhibited mirror-image circular dichroism signals in the visible region, depending on the chirality of cysteine used during synthesis. Time-dependent electrolyte analyses revealed that the reaction process between [AuCl4]- and cysteine significantly affects the morphology and chiroptical responses of the electrodeposited gold nanostructures. Finally, the resulting films showed significantly enhanced SERS signals and enabled discrimination between chiral enantiomers through differences in their SERS spectra, demonstrating their potential as label-free chiral molecular sensing platforms.
Chiral gold nanostructures were deposited on the coral-like gold substrate from an electrolyte containing HAuCl4, KCl, and either L- or D-cysteine, based on a one-step electrodeposition method for chiral plasmonic gold nanostructures. The obtained film exhibited mirror-image circular dichroism signals in the visible region, depending on the chirality of cysteine used during synthesis. Time-dependent electrolyte analyses revealed that the reaction process between [AuCl4]- and cysteine significantly affects the morphology and chiroptical responses of the electrodeposited gold nanostructures. Finally, the resulting films showed significantly enhanced SERS signals and enabled discrimination between chiral enantiomers through differences in their SERS spectra, demonstrating their potential as label-free chiral molecular sensing platforms.