Recent advances in optical gas sensors for carbon dioxide detection

Carbon dioxide (CO2) is a colorless and odorless gas. The imbalanced CO2 concentrations can have detrimental effects, therefore numerous CO2 gas sensors have been developed for various applications. Among these, optical CO2 gas sensors have emerged as a rapidly growing analytical technique due to their exceptional reliability. However, there has been a lack of comprehensive systematic reviews in optical CO2 gas sensors since 2012. This review seeks to explore diverse strategies to enhance the sensitivity, detection range, limit of detection, and response time of optical CO2 gas sensors. Additionally, this review categorizes optical CO2 gas sensors into eight types and discusses the performance of these sensors based on their specific detection methods, which include infrared, photoacoustic spectroscopy, fluorescent, optical fiber, optical resonator, phosphorescent, surface plasmon resonance and optical colorimetric. This review sheds light on the innovative strategies employed to enhance optical CO2 gas sensors, outlining their potential benefits.