Detection of 4-aminothiophenol with core-shell structured Ag@ZnS as a surface enhanced Raman scattering substrate

Abstract

4-Aminothiophenol (4-ATP, a toxic pesticide intermediate) residues in waste water endanger water ecology and human health. Therefore, the development of reliable surface-enhanced Raman scattering (SERS) substrate is a promising strategy for monitoring and preventing 4-ATP pollution. In this work, a core-shell structured Ag@ZnS hybrid, consisting of Ag nano-core and ZnS nano-shell, was fabricated and employed as a SERS substrate to detect 4-ATP. Owing to the specific core-shell structure, epy as-prepared Ag@ZnS substrate is stable against oxidation and spontaneous agglomeration of Ag NPs, enjoying good stability and uniform hot spots. Moreover, the formation of heterostructure between Ag-core and ZnS-shell offered a remarkable chemical enhancement for the Raman signals. The optimized Ag@ZnS substrate showed high sensitivity for rhodamine 6 G (R6G, 10−9 M) and methylene blue (10−8 M) probes, as well as 4-ATP (10−8 M) target analyte. Likewise, the superior reproducibility (RSD<5.50 %, n = 16) and good stability (79.5 % of initial strength after 28 days) for 4-ATP makes this substrate a good candidate for actual determination of trace 4-ATP. This work proposes a strategy to fabricate a reliable SERS substrate with high sensitivity and superior reproducibility, and the designed Ag@ZnS substrate may be applicable to monitor 4-ATP residues in wastewater.