Recent Advances in Metal-Organic Framework-Integrated Nanocomposite Hydrogels for Sensors and Sensing Systems

Metal-organic frameworks (MOFs) are versatile crystalline porous materials with large surface areas, tunable pore architectures, and modular chemical functionalities, enabling diverse applications in materials science and engineering. Hydrogels, with their softness, high water content, biocompatibility, and responsiveness to external stimuli, have been widely explored as smart platforms for flexible electronics and sensing technologies. Integrating MOFs into hydrogel networks synergistically combines the advantages of both material classes, yielding multifunctional composites with enhanced structural and functional properties. MOF–hydrogel composites overcome the limitations of each component, offering improved mechanical robustness, environmental stability, and dynamic responsiveness, making them highly promising for next-generation sensing systems. This review provides a comprehensive overview of recent advances in the synthesis, structural design, and characterization of MOF–hydrogel composites, with a focus on their applications in optical, electrochemical, and electromechanical sensing. Their use across healthcare diagnostics, environmental monitoring, food safety, public health, and flexible electronics is discussed. We highlight how MOF–hydrogel integration influences key sensing metrics such as selectivity, sensitivity, adaptability, detection limits, long-term stability, and dynamic working range. In summary, this review highlights the crucial role of MOF–hydrogel composites in advancing high-performance sensing technologies, outlining key challenges and future directions to inform ongoing research in this field.