a review on chemiresistive gas sensors: basic concepts, evolution, and perspective

With rapid advancements across industry, technology, and medicine, the demand for efficient gas and vapor detection has intensified. among various sensing technologies, chemiresistor gas sensors have emerged as a leading choice due to their affordability, compactness, broad sensitivity range, and user-friendly operation. these sensors play a crucial role in applications spanning environmental monitoring, industrial safety, and healthcare. this review provides a comprehensive overview of chemiresistor gas sensors, beginning with their fundamental principles and operational mechanisms. key performance factors, such as sensitivity, response time, selectivity, and stability, are examined, while the material innovations driving their progress are also considered. the evolution of these sensors is explored through recent research studies, shedding light on both breakthroughs and persistent challenges, including issues of selectivity and environmental interference. finally, future perspectives are discussed, highlighting emerging technologies such as ai-assisted sensing, flexible electronics, and sustainable sensor materials that could shape the next generation of chemiresistor-based detection.