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

Area of Science:

• Materials Science
• Chemical Sensing
• Nanotechnology

Background:

• Recognition layer materials are vital for chemical sensor functionality.
• Advancements in 2D materials boost sensor development, but controlled fabrication of large-scale, highly active recognition layers is key for sensitivity, especially in trace detection.
• Achieving high sensitivity in sensors requires optimized recognition layers with abundant active sites.

Purpose of the Study:

• To develop a strategy for controlled preparation of centimeter-scale non-layered ultrathin β-In₂S₃ materials.
• To design ultrasensitive mercury ion (Hg²⁺) sensors using these tailored materials.
• To demonstrate the sensor's capability for selective and highly sensitive Hg²⁺ detection, even in complex matrices like tap water.

Main Methods:

• Fabrication of centimeter-scale non-layered ultrathin β-In₂S₃ materials with tailored high-active sites.
• Design and testing of Hg²⁺ sensors based on the synthesized β-In₂S₃ recognition layers.
• Evaluation of sensor selectivity and sensitivity, including detection limits and performance in a tap water matrix.

Main Results:

• Successful controlled preparation of centimeter-scale non-layered ultrathin β-In₂S₃ materials.
• Demonstrated ultrasensitive and selective detection of Hg²⁺ at the 1 aM level, attributed to Hg-S bonding at highly active sites.
• Validated excellent sensor performance for Hg²⁺ detection in a tap water sample matrix.

Conclusions:

• Non-layered ultrathin β-In₂S₃ materials with tailored high-active sites are pivotal for superior sensing performance.
• The developed sensor offers a proof-of-concept for utilizing non-layered 2D films in high-performance chemical sensors.
• This approach highlights the potential of non-layered 2D materials for diverse analyte sensing applications.