{
  "abstract": "Bimetallic nanoparticles have attracted significant interest in Surface-Enhanced Raman Scattering (SERS) due to their superior optical and synergistic properties. In this study, layered Ag@Au bimetallic nanostructures were fabricated on Indium Tin Oxide (ITO) glass via a surfactant-free electrochemical approach combining linear sweep voltammetry (LSV) and chronoamperometry (CA). This method rapidly yields clean, highly active plasmonic interfaces, effectively eliminating the competitive adsorption typically caused by chemical stabilisers. By featuring a rugged morphology and an exposed bimetallic interface, the optimal substrate generates abundant electromagnetic hot spots to deliver superior SERS sensitivity for Nile Blue A (NBA). Interestingly, the empirical spectra exhibited a highly selective, vibrational-mode-dependent signal amplification, indicating a restricted, perpendicular adsorption orientation of the NBA molecules within the bimetallic nanogaps. To fundamentally elucidate the localised Chemical Enhancement (CE) mechanism driving this selective behaviour, Density Functional Theory (DFT) calculations were performed on representative pyramidal clusters. Consistent with the stoichiometry of the superior experimental substrate, the computational models demonstrated that the bimetallic Ag₁₆Au₄ cluster yields the strongest SERS enhancement. Charge density difference (CDD) maps and natural population analysis (NPA) showed that the largest electron transfer from the NBA ligand to the Ag₁₆Au₄ cluster occurred through the interaction between the N atom of the oxazine ring and the Au atom at the top of the cluster, resulting in the greatest enhancement. Hence, this synergistic experimental-theoretical approach paves the way for the design of bimetallic sensors for advanced environmental analysis.",
  "abstract_shown": true,
  "affiliations": [
    "School of Chemistry and Life Sciences, Hanoi University of Science and Technology 1 Dai Co Viet Hanoi Vietnam.",
    "Institute of Research and Development, Duy Tan University Da Nang 550000 Vietnam.",
    "School of Engineering and Technology, Duy Tan University Da Nang 550000 Vietnam mai.nguyenthituyet1@hust.edu.vn ngothichinh@duytan.edu.vn."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Minh Nhat Ngo"
    },
    {
      "affs": [
        0
      ],
      "name": "Hang Thi-Thu Le",
      "orcid": "0000-0003-4230-9498"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Thi Chinh Ngo",
      "orcid": "0000-0002-8206-5996"
    },
    {
      "affs": [
        0
      ],
      "name": "Mai Thi-Tuyet Nguyen",
      "orcid": "0000-0002-8901-2395"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fdegh0f49e3s2.bib",
  "cited_by": 0,
  "doi": "10.1039/d6ra08211d",
  "fulltext_url": "https://europepmc.org/articles/PMC13711122",
  "id": "fdegh0f49e3s2",
  "issns": [
    "2046-2069"
  ],
  "landing_url": "https://europepmc.org/article/MED/42948393",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Chemistry"
    ],
    [
      "openalex",
      "2504|Gold and Silver Nanoparticles Synthesis and Applications"
    ]
  ],
  "openalex": "W7223909409",
  "pdf_url": "https://europepmc.org/articles/PMC13711122?pdf=render",
  "pmcid": "PMC13711122",
  "pmid": "42948393",
  "published": "2026-10-27",
  "publisher": "Royal Society of Chemistry",
  "ris": "https://research.draconitic.com/paper/fdegh0f49e3s2.ris",
  "sources": [
    {
      "first_seen": "2026-10-31T00:20:33Z",
      "native_id": "MED:42948393",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42948393"
    },
    {
      "first_seen": "2026-10-31T12:21:57Z",
      "native_id": "PMC13711122",
      "source": "pmc",
      "url": "https://doi.org/10.1039/d6ra08211d"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2504|Gold and Silver Nanoparticles Synthesis and Applications",
      "subfield": "materials-polymers"
    }
  ],
  "title": "Surfactant-free electrochemical synthesis of layered Ag/Au bimetallic nanostructures as SERS platforms with DFT insights into their interfacial charge transfer mechanism.",
  "title_text": "Surfactant-free electrochemical synthesis of layered Ag/Au bimetallic nanostructures as SERS platforms with DFT insights into their interfacial charge transfer mechanism.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-31T12:21:57Z",
  "url": "https://research.draconitic.com/paper/fdegh0f49e3s2",
  "venue": "RSC advances",
  "versions": []
}