(Gold triangular nanoplate core)@(silver shell) nanostructures as highly sensitive and selective plasmonic nanoprobes for hydrogen sulfide detection

Hydrogen sulfide plays a significant role in living beings, while its abnormal concentration is related to many diseases. Besides, H2S gas is harmful to human beings and the environment. The detection of H2S has therefore attracted much attention in the past several decades. Herein, highly sensitive and selective H2S plasmonic nanoprobes (gold triangular nanoplate core)@(silver shell) (AuTNP@Ag) are reported. By virtue of the high refractive index sensitivity of Au TNPs to the surrounding medium and facile sulfurization of silver by sulfur ions, AuTNP@Ag exhibits great sensitivity to both sulfur ions and H2S gas. The shifts of the plasmon peak are as large as 16 nm for the ventilation of 1 ppm hydrogen sulfide. AuTNP@Ag nanoprobes also exhibit very good sensing linearity at low concentrations of sulfur ions. Moreover, excellent sensing selectivity for sulfur ions is obtained. A type of test gel, which can produce a naked-eye observable color change when exposed to 1-100 ppm hydrogen sulfide gas, is developed using AuTNP@Ag nanoprobes. Owing to the high sensitivity, linearity, and selectivity of the Au TNP@Ag nanoprobes for hydrogen sulfide sensing, this work paves the way for the plasmonic detection of hydrogen sulfide in both biological and environmental applications.