Enhanced semiconductor charge-transfer resonance: Unprecedented oxygen bidirectional strategy

Oxygen bidirectional strategy (simultaneous introduction of oxygen vacancies and oxygen incorporation) was first proposed to increase the semiconductor SERS activity to a noble metal comparable level. • We first proposed oxygen bidirectional strategy to improve the SERS performance. • The great properties further demonstrate the practical value of this substrates. • It shows a high-sensitive SERS activity and low detection limit toward MB molecules. • Focuses on application of semiconductor materials used for contaminates detection. Oxygen is one of the most abundant elements on earth, and even small amounts of oxygen can induce significant changes in material properties. In this study, we combined a non-oxide semiconductor molybdenum disulphide (MoS 2 ) with an oxide semiconductor zinc oxide (ZnO), thereby simultaneously obtaining oxygen vacancies and oxygen incorporations through a novel oxidation-assisted strategy. This strategy amplified interactions between semiconductor substrates and probe molecules and increased charge-transfer resonance, thereby substantially improving the surface-enhanced Raman spectroscopy (SERS) performance of semiconductor materials. The enhancement factor of MoS 2 @ZnO was increased to a value comparable to that of traditional metals, enabling it to detect methylene blue with a limit of detection as low as 10 −12 M. Additionally, a comparison sample (MoS 2 @ZnS) was examined to confirm the unique enhancement effect of the proposed strategy for SERS. The effect of the proposed oxygen bidirectional strategy on the SERS performance of semiconductor substrates can provide new frontiers in the development of ultrasensitive semiconductor technologies.