High-Active Surface of Centimeter-Scale β-In₂S₃ for Attomolar-Level Hg²⁺ Sensing

Recognition layer materials play a crucial role in the functionality of chemical sensors. Although advancements in two-dimensional (2D) materials have promoted sensor development, the controlled fabrication of large-scale recognition layers with highly active sites remains crucial for enhancing sensor sensitivity, especially for trace detection applications. Herein, we propose a strategy for the controlled preparation of centimeter-scale non-layered ultrathin β-In₂S₃ materials with tailored high-active sites to design ultrasensitive Hg²⁺ sensors. Our results reveal that the highly active sites of non-layered β-In₂S₃ materials are pivotal for achieving superior sensing performance. Selective detection of Hg²⁺ at the 1 aM level is achieved via selective Hg-S bonding. Additionally, we evaluate that this sensor exhibits excellent performance in detecting Hg²⁺ in the tap water matrix. This work provides a proof-of-concept for utilizing non-layered 2D films in high-performance sensors and highlights their potential for diverse analyte sensing applications.