Adaptive Integrated-Interface Enabled Highly Stable Ionic Sensing Strategy

Release time：

2025-06-14

Recently, the research team led by Prof. Huang Xingjiu at the Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, developed a highly stable adaptive integrated interface by tailoring the structural adaptability of ionic sensing interfaces.

All-solid-state ion-selective electrodes (ASS-ISEs), as key components of smart biochemical sensors, have demonstrated broad application prospects in recent years.In their prior work, the team developed a series of transducer materials based on a sandwich-type all-solid-state interface structure, enabling highly stable detection of multiple common electrolyte ions.The study reveals that ionic sensing performance is critical for sensor stability and reliability, fundamentally constrained by the material properties and structural features of the sensing interface.

Building on this, the team developed a highly stable adaptive integrated sensing interface based on hexadecyltrimethylammonium (CTA⁺)-tuned lipophilic MoS₂ (2.0 CTA-MoS₂).This interface enables spontaneous seamless integration between the bottom transducer layer and top monolithic sensing structure through spatiotemporal adaptive regulation, ensuring exceptional interfacial adaptability.

Through in-depth study of the interface structure rationality and interaction mechanisms, the team's electrochemical modeling revealed that the adaptive integrated interface system achieves optimal stability with maximum transducer-layer charge current and minimal diffusion current.Synchrotron XAFS studies further revealed a mixed capacitive transduction mechanism driven by lipophilic anion (TFPB⁻) adsorption on 2.0 CTA-MoS₂ surfaces.

For practical validation, the adaptive integrated Cd²⁺-selective interface demonstrated exceptional stability (24-h drift: 5.51±0.32 μV·h⁻¹, 30-day sensitivity loss: 4.77%), high selectivity, and accurate detection of industrial wastewater samples (90–115% recovery), showcasing strong application potential.

Moreover, the team developed a universal cation-selective sensor (K⁺, Na⁺, Ca²⁺, Mg²⁺, Pb²⁺, Cd²⁺, Cu²⁺) with an adaptive integrated interface, demonstrating near-Nernstian responses across a wide linear range.Compared to all-solid-state and monolithic interfaces based on 2.0 CTA-MoS₂, this design significantly enhances sensing interface stability.

This study provides an effective strategy and critical reference for constructing high-performance sensing interfaces.

These findings were published in Advanced Materials. This work was supported by the National Key R&D Program of China and the National Natural Science Foundation of China.