Ultrasensitive Detection of Trace Silver Ions Using MoS-Intercalated LDH Nanosheets Enhanced SPR Sensor.

The widespread use of silver raises concerns about environmental and health risks, necessitating highly sensitive detection methods for trace silver ions (Ag). Surface plasmon resonance (SPR) sensors offer benefits like label-free detection and rapid response, but their sensitivity for Ag detection is limited due to weak ion adsorption. Here, we developed an SPR sensor with MoS-intercalated NiAl-layered double hydroxide (LDH) as the adsorption layer of Ag to enhance detection sensitivity. Our sensor achieves a sensitivity of 254.75 nm/μg/L and detects Ag at a low concentration of 2.8 pM, outperforming various existing sensors. It also shows excellent repeatability, long-term stability, and selectivity, proving effective in real-world environmental samples. This work advances high-performance SPR sensors for heavy metal ion detection.