Excessive H2O content in food will cause the hydrolysis of nutrients and provide a favorable environment for the growth of mycotoxins, thus, developing fast response, low detection limit, and high detection capacity sensors is urgently needed for food quality and safety. In this work, we developed two borate-ester-based covalent organic frameworks (COF-5 and COF-10) with high specific surface areas (1189.0 m2·g−1 and 1105.1 m2·g−1), which exhibited rapid response (COF-5 about 40 s and COF-10 about 35 s), good linearity (COF-5:R2=0.9981 and COF-10:R2=0.9993), and low detection limits (LODCOF-5=0.044 v/v% and LODCOF-10=0.016 v/v%). DFT theoretical calculation demonstrated that H2O participated in the partial hydrolysis of the B-O bond, resulting in the enhancement of fluorescence. Based on the good fluorescence properties, these two probes had been successfully used to quantificationally detect H2O content in honey, corn starch, and milk powder with satisfactory results, indicating an excellent application potential in the food field.

中文翻译：

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构建具有高比表面积的硼酸酯基 COF 用于食品领域 H2O 含量的检测


食品中 H2O 含量过高会导致营养物质水解，为霉菌毒素的生长提供有利环境，因此，开发响应快、检出限低、检出能力高的传感器是食品质量安全亟需的。在这项工作中，我们开发了两种基于硼酸盐酯的共价有机框架（COF-5 和 COF-10），具有高比表面积（1189.0 m2·g-1 和 1105.1 m2·g-1），表现出快速响应（COF-5 约 40 s，COF-10 约 35 s）、良好的线性（COF-5：R2=0.9981 和 COF-10：R2=0.9993）和低检测限（LODCOF-5=0.044 v/v% 和 LODCOF-10=0.016 v/v%）。DFT 理论计算表明，H2O 参与了 B-O 键的部分水解，导致荧光增强。基于良好的荧光特性，这两种探针已成功用于定量检测蜂蜜、玉米淀粉和奶粉中的 H2O 含量，结果令人满意，在食品领域具有极好的应用潜力。