Metal oxide semiconductor gas sensing materials for early lung cancer diagnosis

The urgency of early lung cancer (LC) diagnosis and treatment has been more and more significant. Exhaled breath analysis using gas sensors is a promising way to find out if someone has LC due to its low-cost, non-invasive, and real-time monitoring compared with traditional invasive diagnostic techniques. Among sensor-based gas detection techniques, metal oxide semiconductor’s gas sensors are one of the most important types. This review presents the-state-of-art in metal oxide gas sensors for the diagnosis of early LC. First, the exhaled breath biomarkers are described with emphasis on the concentration of abnormal volatile organic compounds (VOCs) caused by the metabolic process of LC cells. Then, the research status of metal oxide gas sensors in LC diagnosis is summarized. The sensing performance and enhancement strategy of biomarkers provided by metal oxide semiconductor materials are reviewed. Another effective way to improve VOC detection performance is to build a gas sensor array. At the same time, various gas sensors combined with self-powered techniques are mentioned to display a broad development prospect in breath diagnosis. Finally, metal oxide gas sensor-based LC diagnosis is prospected.