Disclosed are a method of detecting a leak of fluoroolefin compositions and sensors used therefor. In particular, the method is particularly useful for detecting a leak of a fluoroolefin refrigerant composition from a cooling system of an automotive vehicle. Such fluoroolefin refrigerant compositions have double bond structures which make them particularly well suited with sensing technologies, including: infrared sensors, UV sensors, NIR sensors, ion mobility or plasma chromatographs, gas chromatography, refractometry, mass spectroscopy, high temperature thick film sensors, thin film field effect sensors, pellistor sensors, Taguchi sensors and quartz microbalance sensors.