A dual-mode foam sensor employing Ti3C2Tx/In2O3 composites for NH3 detection with memory function and body movement monitoring for kidney disease diagnosis

Abstract

Research on non-invasive nephropathy testing has been a prominent area of interest both domestically and internationally. However, the conventional NH₃ measurement using gas sensors is distorted by other exhaled components, compromising assessment precision. In this study, a bi-functional sensing platform based on Ti₃C₂T_x/In₂O₃ nanocomposites modified TPU foam sensor was constructed to realize the detection of gas and motion bio-signals of kidney diseases. By combining surface-functionalized In₂O₃ nanotubes with Ti₃C₂T_x nanoflakes, the achieved nanocomposites showed a strong synergistic effect and structural stability. In addition, by depositing Ti₃C₂T_x/In₂O₃ nanocomposites onto the TPU foam substrate, the detection of multiple external stimuli with non-interfering in a flexible and room temperature way can be achieved. The developed Ti₃C₂T_x/In₂O₃ foam sensor exhibits the capability to detect NH₃ gas as low as 1 ppm with memory function, demonstrating its excellent practical utility in complex exhaled environments. Moreover, the sensor displays a remarkable ability to accurately interpret human motion signals, including leg flexion and extension. The Ti₃C₂T_x/In₂O₃ foam sensor was successfully deployed for the comprehensive monitoring of abnormal physiological signals in patients with kidney disease, encompassing simulated NH₃ exhalation patterns, and limb flexion–extension signals. This study introduces some ideas to develop a multifunctional sensing platform for disease diagnosis in a non-invasive way.