Graphene-integrated toroidal resonance metasurfaces used for picogram-level detection of chlorothalonil in the terahertz region
Maosheng Yang, Haiyun Yao, Yu‐Ying Lu, Peipei Li, Binbin Du, Qilin Ma, Dandan Liu, Tan Zhang, Jie Fang, Tongling Wang, Xin Yan, Gang Zhang, Lanju Liang, Qilin Yang, Yaru Wang, Meng Wang, Zijie Dai, Jingjing Zhang, Yunxia Ye, Xiaoxian Song, Haiting Zhang, Xundong Ren, Jianquan Yao
Abstract
Toroidal dipole resonance can significantly reduce radiation loss of materials, potentially improving sensor sensitivity. Generally, toroidal dipole response is suppressed by electric and magnetic dipoles in natural materials, making it difficult to observe experimentally. However, as 2D metamaterials, metasurfaces can weaken the electric and magnetic dipole, enhancing toroidal dipole response. Here, we propose a new graphene-integrated toroidal resonance metasurface as an ultra-sensitive chemical sensor, capable of qualitative detection of chlorothalonil in the terahertz region, down to a detection limit of 100 pg/mL. Our results demonstrate graphene-integrated toroidal resonance metasurfaces as a promising basis for ultra-sensitive, qualitative detection in chemical and biological sensing.