2D TiS2‐Nanosheet‐Coated Concave Gold Arrays with Triple‐Coupled Resonances as Sensitive SERS Substrates
Yuancai Ge, Ying Yang, Yajie Zhu, Meiling Yuan, Liangbin Sun, Danfeng Jiang, Xiaohu Liu, Qingwen Zhang, Jinyi Zhang, Yi Wang- Biomaterials
- Biotechnology
- General Materials Science
- General Chemistry
Abstract
Herein, a hybrid substrate for surface‐enhanced Raman scattering (SERS) is fabricated, which couples localized surface plasmon resonance (LSPR), charge transfer (CT) resonance, and molecular resonance. Exfoliated 2D TiS2 nanosheets with semimetallic properties accelerate the CT with the tested analytes, inducing a remarkable chemical mechanism enhancement. In addition, the LSPR effect is coupled with a concave gold array located underneath the thin TiS2 nanosheet, providing a strong electromagnetic enhancement. The concave gold array is prepared by etching silicone nanospheres assembled on larger polystyrene nanospheres, followed by depositing a gold layer. The LSPR intensity near the gold layer can be adjusted by changing the layer thickness to couple the molecular and CT resonances, in order to maximize the SERS enhancement. The best SERS performance is recorded on TiS2‐nanosheet‐coated plasmonic substrates, with a detectable methylene blue concentration down to 10−13