Key Laboratory of Catalytic Conversion and Clean Energy in Universities of Shandong Province & Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, PR China.
Key Laboratory of Catalytic Conversion and Clean Energy in Universities of Shandong Province & Key Laboratory of Life-Organic Analysis of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, PR China.
Anal Chim Acta. 2024 Aug 29;1319:342963. doi: 10.1016/j.aca.2024.342963. Epub 2024 Jul 9.
NO and S are two kinds of common toxic anions widely distributed in environmental water, soil and food products. Human beings have suffered a lot of diseases from intake of excessive NO or S, i.e., infantile methemoglobin, cancer and even to death. Although tremendous efforts have been afforded to monitor NO and S, most were high instrument-depended with complex processing procedures. To keep food safety and to protect human health, it will be a huge challenge to develop a convenient and efficient way to monitor S and NO in practice.
A kind of folic acid capping Bi-doped Ag quantum dots (FA@Bi-Ag QDs) was developed for the first time by one-pot homogeneous reduced self-assembly. Not only did FA@Bi-Ag QDs possess intrinsic fluorescent property, it expressed synergistic peroxidase-like activity to catalyze the redox of 3,3',5,5'-tetramethylbenzidine (TMB) and HO with K/v of 0.087 mM/6.61 × 10 M s and 6.42 mM/6.25 × 10 M s respectively. Interestingly, trace S could exclusively alter its fluorescent property and peroxidase-like activity, exhibiting significant hypochromic and "turn-on" fluorescent effects. While trace NO could make FA@Bi-Ag QDs-TMB-HO system hyperchromic. Under the optimized conditions, FA@Bi-Ag QDs were applied for dual-mode recognition of S and visual sensing of NO in real food samples with satisfactory recoveries, i.e., 100.7-107.9 %/95.8-104.7 % and 97.2-104.8 % respectively. The synergistic enzyme-mimic mechanism of FA@Bi-Ag QDs and its selective response mechanisms to S and NO were also proposed.
This represents the first nanozyme-based FA@Bi-Ag QDs system for dual-mode recognition of S and visual sensing of NO, well meeting the basic requirement in drinking water set by WHO. It will offer a promising way for multi-mode monitoring of different pollution using the same nanozyme-based sensor.
NO 和 S 是两种常见的有毒阴离子，广泛分布于环境水、土壤和食品产品中。人类因摄入过量的 NO 或 S 而遭受了许多疾病，例如婴儿高铁血红蛋白症、癌症，甚至死亡。尽管人们已经付出了巨大的努力来监测 NO 和 S，但大多数方法都高度依赖仪器，且处理过程复杂。为了确保食品安全和保护人类健康，开发一种方便、高效的方法来实际监测 S 和 NO 将是一个巨大的挑战。
首次通过一锅法均相还原自组装制备了叶酸封端的 Bi 掺杂 Ag 量子点（FA@Bi-Ag QDs）。FA@Bi-Ag QDs 不仅具有内在的荧光性质，还表现出协同过氧化物酶样活性，能够催化 3,3',5,5'-四甲基联苯胺（TMB）和 HO 的氧化还原反应，K/v 分别为 0.087 mM/6.61×10 M s 和 6.42 mM/6.25×10 M s。有趣的是，痕量 S 可以单独改变其荧光性质和过氧化物酶样活性，表现出明显的减色和“开启”荧光效应。而痕量 NO 可以使 FA@Bi-Ag QDs-TMB-HO 体系增色。在优化条件下，FA@Bi-Ag QDs 被用于实际食品样品中 S 和 NO 的双模态识别及可视化传感，回收率为 100.7-107.9%/95.8-104.7%和 97.2-104.8%。还提出了 FA@Bi-Ag QDs 的协同酶模拟机制及其对 S 和 NO 的选择性响应机制。
这是第一个基于纳米酶的 FA@Bi-Ag QDs 系统，用于 S 的双模态识别和 NO 的可视化传感，很好地满足了世界卫生组织对饮用水的基本要求。它将为使用相同的基于纳米酶的传感器对不同污染物进行多模态监测提供一种有前景的方法。
