Trimethylamine (TMA) is one of the important chemical indexes to judge the freshness of marine fish. It is necessary to develop a low temperature TMA sensor to help the monitoring and prediction of the quality of marine fish in cold chain. Herein, a flexible low temperature TMA gas sensor featuring antifreezing and superior mechanical properties was developed based on the Au nanoparticle-modified MXene (MXene@Au) composite. MXene@Au was synthesized and then polymerized with a hydrogel composed of acrylamide (AM), N,N′-methylenebisacrylamide (BIS), sodium carboxymethyl cellulose (CMC), and EG, and the resultant MXene@Au hydrogel was found to exhibit excellent antifreezing performance even at extremely low temperature as well as high tensile strength, ultrastretchability, and toughness, which enabled an efficient gas sensing platform for TMA detection at low temperature. The TMA sensing properties of the flexible MXene@Au DN hydrogel sensor at 25 °C and a low temperature of 0 °C were studied, and a linear relationship between TMA sensitivity and concentration was built. The excellent sensing properties were maintained even under deformation. The application of the MXene@Au DN hydrogel sensor in detection of fish freshness at 0 °C was investigated. The result indicated the potential application of the flexible MXene@Au DN hydrogel gas sensor in dynamic quality monitoring and prediction of marine fish products during its transportation and storage in the cold chain.

中文翻译：

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用于低温三甲胺气体传感的坚韧抗冻 MXene@Au 水凝胶

三甲胺（TMA）是判断海鱼新鲜度的重要化学指标之一。有必要开发低温TMA传感器，以帮助对冷链海鱼的质量进行监测和预测。在此，基于金纳米粒子改性的 MXene (MXene@Au) 复合材料开发了一种具有抗冻性和优异机械性能的柔性低温 TMA 气体传感器。MXene@Au 被合成，然后与由丙烯酰胺 (AM)、N、N组成的水凝胶聚合'-亚甲基双丙烯酰胺 (BIS)、羧甲基纤维素钠 (CMC) 和 EG 以及所得的 MXene@Au 水凝胶被发现即使在极低温度下也表现出优异的防冻性能以及高拉伸强度、超拉伸性和韧性，这使得一种用于低温下 TMA 检测的高效气体传感平台。研究了柔性 MXene@Au DN 水凝胶传感器在 25°C 和 0°C 低温下的 TMA 传感特性，建立了 TMA 灵敏度与浓度之间的线性关系。即使在变形下也能保持优异的传感特性。研究了 MXene@Au DN 水凝胶传感器在 0°C 鱼新鲜度检测中的应用。