Dual LSPR and CT synergy: 3D urchin-like Au@W18O49 enables highly sensitive in-situ SERS detection of dissolved furfural in insulating oils

• Published in: Talanta (Oxford) 2025-01, Vol.281, p.126854, Article 126854
• Main Authors: Wang, Changding, Lei, Yu, Zhang, Sida, Wang, Ziyi, Wang, Miaolin, Ming, Zifeng, Liu, Ruiqi, Yang, Da, Zhang, Zhixian, Wang, Pinyi, Wan, Fu, Chen, Weigen
• Format: Article
• Language: English
• Subjects: Au@W18O49; Dual LSPR + CT; Furfural; In-situ detection; Insulating oil; SERS
• ISSN: 0039-9140; 1873-3573; 1873-3573
• DOI: 10.1016/j.talanta.2024.126854

Assessing the levels of furfural in insulating oils is a crucial technical method for evaluating the degree of aging and mechanical deterioration of oil-paper insulation. The surface-enhanced Raman spectroscopy (SERS) technique provides an effective method for enhancing the sensitivity of in-situ detection of furfural. In this study, a homogeneous three-dimensional (3D) urchin-like Au@W18O49 heterostructure was synthesized as a SERS substrate using a straightforward hydrothermal method. The origin of the superior Raman enhancement properties of the 3D urchin-like heterostructures formed by the noble metal Au and the plasmonic semiconductor W18O49, which is rich in oxygen vacancies, is analyzed experimentally in conjunction with density-functional theory (DFT) calculations. The Raman enhancement is further amplified by the remarkable dual localized surface plasmon resonance (LSPR) effect, which generates a strong local electric field and creates numerous "hot spots," in addition to the interfacial charge transport (CT). The synergistic effect of these factors results in the 3D urchin-like Au@W18O49 heterostructure exhibiting exceptionally high SERS activity. Testing the rhodamine 6G (R6G) probe resulted in a Raman enhancement factor of 3.41 × 10−8, and the substrate demonstrated excellent homogeneity and stability. Furthermore, the substrate was effectively utilized to achieve highly sensitive in-situ surface-enhanced Raman scattering (SERS) detection of dissolved furfural in complex plant insulating oils. The development of the 3D urchin-like Au@W18O49 heterostructure and the exploration of its enhancement mechanism provide theoretical insights for the advancement of high-performance SERS substrates. [Display omitted] •3D urchin-like Au@W18O49 heterostructure as a high-performance SERS substrate.•The SERS substrate exhibits a high SERS enhancement factor, excellent homogeneity and long-term durability.•The substrate can be used for the in-situ detection of furfural in complex insulating oil environments.•Experiments combined with DFT calculations reveal the synergistic enhancement mechanism of dual LSPR and CT.