Cu–Gallate MOF–Chitosan Hybrid Membrane for Low-Power, Non-Invasive Acetone Sensing: Toward Early-Stage Diabetes Detection

The precise and noninvasive detection of volatile organic compounds (VOCs) is of growing importance in medical diagnostics, health monitoring, and environmental assessment. Among these VOCs, acetone in human breath serves as a key biomarker for the early detection of diabetes. In this work, we report the development of a high-performance composite membrane sensor based on a copper gallate metal-organic framework (Cu-gallate MOF) integrated with chitosan (CS) and doped with ionic liquid glycerol (IL). The incorporation of chitosan significantly improved membrane conductivity and structural stability, while hydrogen-bonding interactions enhanced acetone selectivity. As a result, the Cu-gallate MOF/CS/IL sensor achieved a remarkable detection limit of 0.25 ppm at an operating temperature of 80 °C, with rapid response (27 s) and recovery (10 s) times. The sensor further demonstrated excellent selectivity, long-term durability, and reproducible performance under practical testing conditions. These findings highlight the potential of MOF-based mixed-matrix membranes as a cost-effective and energy-efficient platform for real-time breath analysis, providing a promising pathway toward early diagnosis and monitoring of diabetes.