Facile Reduction Method Synthesis of Defective MoO 2– x Nanospheres Used for SERS Detection with High Chemical Enhancement

作者：Yu Cao, Pei Liang, Qianmin Dong, Dan Wang, Zhang De, Lisha Tang, Le Wang, Shangzhong Jin, Dejiang Ni, Zhi Yu · 发表于：Analytical Chemistry · 年份：2019 · DOI：10.1021/acs.analchem.9b02394 · 被引用次数：71 · 研究领域：Gold and Silver Nanoparticles Synthesis and Applications、Advanced Nanomaterials in Catalysis、Advanced biosensing and bioanalysis techniques

Recently, more and more attention has been given to a semiconductor oxide-based surface-enhanced Raman spectroscopy substrate for its great stability and biocompatibility. However, its poor SERS sensitivity limits the applications of semiconductor oxide SERS substrates. In this paper, we provide a facile reduction method to modulate oxygen vacancy concentrations in oxide SERS substrates. Using MoO 2 as an example, the resonance coupling as well as charge transfer between the semiconductor oxide SERS substrate and the target molecules were promoted for the reason of artificial oxygen vacancy embodied in the Raman signals being improved. By using the TEM, SEM, and XPS measurements, we confirmed that we successfully prepared defective MoO 2– x with a polycrystalline surface. MoO 2– x modulated oxygen vacancy treated with 6 wt % Li shows a very high detection sensitivity of 10 –8 M (4.79 ug/L) for R6G, and the intensity of the Raman signal was highly enhanced. Because of the existence of defective energy levels, resonance coupling, as well as charge transfer between semiconductor and molecules, was obviously promoted. More importantly, the method of modulating oxygen vacancy can be widely used in semiconductor oxide materials for its chemical enhancement capacity can be promoted by artificial oxygen vacancy.