Recent advances in 2D-material-based wearable VOC and humidity sensors
The rapid expansion of wearable electronics has created an urgent need for flexible, lightweight sensors capable of real-time monitoring of volatile organic compounds and humidity for healthcare and environmental applications. This mini review critically examines recent advances in wearable VOC and humidity sensors based on two-dimensional (2D) materials, including graphene derivatives, MXenes, and transition metal dichalcogenides (TMDs). These materials offer unique advantages—high surface area, mechanical flexibility, tunable surface chemistry, and room-temperature operability—making them ideal for integration into wearable platforms such as polymers, textiles, and paper substrates. We comprehensively summarize recent progress in 2D-material-based sensors for exhaled breath analysis, respiratory monitoring, and disease diagnostics, highlighting key enhancement strategies including heterostructure engineering, conductive polymer incorporation, defect engineering, and metal-organic framework integration. Persistent challenges such as poor selectivity, humidity interference, long-term stability, and scalable fabrication are discussed. Finally, we present future perspectives on AI-assisted data fusion, multifunctional wearable systems, biodegradable substrates, and self-healing electronics, providing a roadmap for next-generation personalized healthcare and environmental monitoring technologies.