Nanoporous graphene oxide/molybdenum disulfide based on quartz crystal microbalance gas sensor for total volatile basic nitrogen detection in salmon meat

Total volatile basic nitrogen (TVB-N) is a significant indicator for meat freshness evaluation. In this study, a simple hydrothermal method was utilized to synthesize the nanoporous graphene oxide/ molybdenum disulfide (NGO/MoS 2 ) nanocomposites. The optimum detection effect of the polymerization process was optimized by using different proportions of NGO in the solution, and the NGO/MoS 2 based quartz crystal microbalance (QCM) gas sensor was used to detect TVB-N in salmon meat for assessing its freshness. The NGO/MoS 2 composites with different mass ratios were synthesized by hydrothermal method, and were characterized by FT-IR, Raman, XPS, SEM and TEM. The results showed that NGO/MoS 2 had both functional groups on graphene oxide (GO) surface, marginal sites and active sites of MoS 2 . The NGO/MoS 2 based QCM gas sensor was highly sensitive to TVB-N gases such as trimethylamine, dimethylamine and ammonia. Compared with other gases, NGO/MoS 2 sensor had higher selectivity to TVB-N gases. The high responses of NGO/MoS 2 based sensor to TVB-N gases were attributed to the positive synergistic effect of the porous structure, surface functional groups and high specific surface area of NGO and MoS 2 . Finally, the sensor has been applied for predicting salmon meat freshness.