Polyhedral silver clusters as single molecule ammonia sensor based on charge transfer-induced plasmon enhancement

The unique plasmon resonance characteristics of nanostructures based on metal clusters have always been the focus of various plasmon devices and different applications. In this work, the plasmon resonance phenomena of polyhedral silver clusters under the adsorption of NH₃, N₂, H₂, and CH₄ molecules are studied by using time-dependent density functional theory. Under the adsorption of NH₃, the tunneling current of silver clusters changes significantly due to the charge transfer from NH₃ to silver clusters. However, the effects of N₂, H₂, and CH₄ adsorption on the tunneling current of silver clusters are negligible. Our results indicate that these silver clusters exhibit excellent selectivities and sensitivities for NH₃ detection. These findings confirm that the silver cluster is a promising NH₃ sensor and provide a new method for designing high-performance sensors in the future.