▎ 摘　　要

NOVELTY - Detecting freshness of salmon fish based on quartz crystal microbalance (QCM) gas sensitive sensor involves modifying graphene oxide, titanium carbide, carboxylated multi-walled carbon nanotube, and graphite alkyne oxide in the QCM gold electrode to detect four iconic volatile gases during the putrefaction process of salmon such as trimethylamine, dimethylamine, formaldehyde and ammonia, judging the freshness of salmon fish by detecting the target gas, comparing the detection of salmon fish, visualizing response data of the sensor by principal component analysis (PCA), and first two principal components (PCs) explains 98.8% of total contribution variance, using quadratic support vector machine (QSVM) to establish further judging model with the classification result of 100%, comparing the detection results with the total volatile base nitrogen (TVB-N) content to judge the freshness of salmon fish. USE - Detecting freshness of salmon fish used in food, gas sensor and surface science application. ADVANTAGE - The QCM sensor modified by the four sensing material have excellent sensitivity, selectivity and repeatability to the corresponding target gases.