Advances in methane sensor development: From fundamentals to field deployment and future perspective

Methane plays a dual role in modern society, serving as a valuable energy resource while also being a major contributor to climate change and a serious safety hazard due to its explosivity. As a result, the ability to reliably detect and quantify methane is critical across a wide range of sectors, including mining, oil and gas, agriculture, and waste management. Over the past decades, a diverse array of methane sensing technologies has been developed to address these needs, spanning laboratory-scale devices, field-deployable sensors, and large-area monitoring platforms. This review examines these technologies from a practical, application-driven perspective, covering their underlying sensing principles, material systems, performance characteristics, and typical deployment contexts. Point sensors such as catalytic pellistors, non-dispersive infrared sensors, and chemiresistive devices remain central to localized safety monitoring and leak detection, where fast response and robust operation are essential. At larger spatial scales, mobile and fixed open-path optical techniques enable real-time monitoring of methane over distances ranging from tens of meters to several kilometres, while airborne and satellite-based hyperspectral imaging now plays an increasingly important role in identifying large emission sources and validating regional and global emission inventories. Rather than viewing these approaches in isolation, this review frames methane detection as a complementary, multi-scale sensing hierarchy, in which different technologies address distinct but interconnected monitoring challenges. Particular attention is given to the trade-offs that currently limit widespread deployment, including selectivity, long-term stability, environmental interference, and cost. Finally, emerging trends in sensor integration, data fusion, and the coupling of sensing platforms with Internet of Things (IoT) infrastructure and AI-based analytics are discussed as key enablers for scalable, real-time methane monitoring and more effective emission mitigation strategies.