Laser-Engineered MXene Heterostructure for Wearable Ammonia Sensors

Clinical Snapshot

Key Findings

• P Value: Not reported

• Effect Size: Five-fold improvement over conventional MXene-based sensors

• Primary Outcome: Sensor sensitivity of 2.5% ppm-1 for ammonia detection

• Nnt Or Sensitivity: Detection limit: 0.2 ppm ammonia with >10% response maintained at 90% relative humidity

• Confidence Interval: Not reported

Clinical Application

High technical feasibility for wearable integration, but requires clinical validation and regulatory approval Potential TGA medical device pathway required; could complement existing liver function monitoring under Medicare if clinically validated Patients requiring non-invasive monitoring of hepatorenal function and metabolic disorders through breath ammonia analysis

Abstract

Exhaled ammonia is a vital biomarker for clinical diagnosis of hepatorenal dysfunction and metabolic disorders. However, conventional sensors are often limited by complex fabrication processes, high operating temperatures, and particularly, compromised selectivity under high-humidity conditions. To overcome these challenges, we developed a laser-assisted heterostructure engineering strategy that enables in situ construction of Schottky barrier in MXene/polyacrylonitrile (PANF) nanofiber membranes, termed as a laser-engineered MXene (LEM) sensor. The laser micropatterning technique provides three key innovations: (1) kinetically controlled deposition of MXene (Ti3C2Tx) with minimal oxidation, (2) self-aligned formation of Schottky barriers through interfacial TiO2/MXene heterojunctions, and (3) creation of hierarchical gas transport channels within the 3D nanofibrous matrix. The optimized LEM sensor exhibits outstanding sensitivity (2.5% ppm-1), a low detection limit (0.2 ppm) at room temperature (25 °C), and humidity operation stability (> 10% response at 90% relative humidity). This performance surpasses that of conventional MXene-based sensors by fivefold in sensitivity without the need for thermal activation. Mechanism studies reveal that the laser-induced heterointerface facilitates charge transfer-dominated ammonia adsorption and desorption kinetics, while the nanofibrous architecture ensures molecular accessibility to active sites. This ambient-processable and scalable fabrication method paves the way for advanced wearable breath analyzers by combining manufacturing versatility, humidity-resistant excellent selectivity, and energy-efficient operation.