▎ 摘　　要

NOVELTY - Sensor (10) comprises a board (11); a graphene sheet (12) positioned on the board; and copper oxide nano particle (13) having size of 10-20 nm on the graphene sheet, where the graphene sheet is immersed in aqueous solution containing 1.2 wt.% copper oxide, rotating and stirring at 1500 revolution/minute. USE - The sensor and device are useful for detecting ammonia gas (claimed). ADVANTAGE - The sensor has high sensitivity, high selectivity, fast saturation, and fast recovery time, changes electrochemical properties of graphene, anis easy to produce. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for device comprising sensor, an electrode connected to both ends of the graphene sheet, and power supply for driving the sensor. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the sensor. Sensor (10) Board (11) Graphene sheet (12) Copper oxide nano particle (13)