School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, 510006, China; Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products, Guangzhou Higher Education Mega Centre, Guangzhou, 510006, China.
School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, 510006, China; Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products, Guangzhou Higher Education Mega Centre, Guangzhou, 510006, China; Food Refrigeration and Computerized Food Technology (FRCFT), Agriculture and Food Science Centre, University College Dublin, National University of Ireland, Belfield, Dublin, 4, Ireland.
Anal Chim Acta. 2022 Aug 15;1221:340122. doi: 10.1016/j.aca.2022.340122. Epub 2022 Jun 25.
Given the ever-growing food safety issues, the establishment of efficient approaches for monitoring food freshness attracts increasing attention. Volatile basic nitrogens (VBNs), including biogenic amines and ammonia, serve as an important biomarker for monitoring food freshness. In this study, a novel VBNs-responsive tag using glutathione capped copper nanoclusters (GSH-CuNCs) aggregates was developed as a fluorescent probe for in situ and real-time visual monitoring of salmon freshness, and the prepared GSH-CuNCs aggregates were characterized and their sensitivity for detecting VBNs using biogenic amines and ammonium hydroxide as the model targets was evaluated. Based on their remarkable response in liquid status, the GSH-CuNCs aggregates-based tag as a gas indicator was then fabricated, which exhibited visible colour changes under UV light as a function of ammonia vapour concentrations. More importantly, through exploring the sensing mechanism of GSH-CuNCs aggregates in VBNs detection, the existence of ligand exchange between the GSH-CuNCs and VBNs was observed and verified for the first time, confirming the effect of hydrogen bonding reported in the literature. Moreover, the GSH-CuNCs aggregates-based tag was applied for quantitative analysis of salmon freshness during different storage periods, which was validated by the standard method for detection of total VBNs in salmon. In addition, a colour card was developed and its feasibility for application in monitoring salmon freshness was validated, which could be used for consumers to obtain the freshness level directly with the naked eye, demonstrating the feasibility of the fabricated tag for real-time and visual monitoring of salmon freshness, thus showing great potentials for its practical applications in the food industry.
鉴于日益严重的食品安全问题，建立有效的方法来监测食品的新鲜度引起了越来越多的关注。挥发性碱性氮（VBNs），包括生物胺和氨，是监测食品新鲜度的重要生物标志物。在这项研究中，开发了一种使用谷胱甘肽封端的铜纳米簇（GSH-CuNCs）聚集体的新型 VBNs 响应标签，作为一种荧光探针，用于原位和实时可视化监测三文鱼的新鲜度，并对制备的 GSH-CuNCs 聚集体进行了表征，并评估了它们对生物胺和氨作为模型目标检测 VBNs 的敏感性。基于它们在液体状态下的显著响应，然后制备了基于 GSH-CuNCs 聚集体的标签作为气体指示剂，其在氨蒸气浓度的作用下在紫外光下显示出可见的颜色变化。更重要的是，通过探索 GSH-CuNCs 聚集体在 VBNs 检测中的传感机制，首次观察到并验证了 GSH-CuNCs 和 VBNs 之间配体交换的存在，证实了文献中报道的氢键的作用。此外，将基于 GSH-CuNCs 聚集体的标签应用于不同储存期三文鱼新鲜度的定量分析，通过检测三文鱼中总 VBNs 的标准方法进行验证。此外，还开发了一个色卡，并验证了其在监测三文鱼新鲜度方面的应用可行性，消费者可以用肉眼直接获得新鲜度水平，这证明了所制备的标签用于实时和可视化监测三文鱼新鲜度的可行性，因此在食品工业中的实际应用具有很大的潜力。
