Yang Chunlei, Xu Guiju, Hou Chenghao, Zhang Hongwei
Institute of Food & Nutrition Science and Technology, Shandong Academy of Agricultural Sciences, Jinan 250100, PR China.
Food Chem X. 2024 Sep 17;24:101843. doi: 10.1016/j.fochx.2024.101843. eCollection 2024 Dec 30.
Gallic acid (GA) is widely used in beverages, food, and other fields as antioxidant. However, GA is slightly toxic and the accumulation of GA is harmful to human body. Therefore, it's vital to develop simple and sensitive detection methods for GA. In this work, a novel ratiometric fluorescent nanoprobe (named CoOOH/OPD/SiNPs) for the GA detection in different foods was designed and prepared. The fluorescence of silicon nanoparticles (SiNPs) at 443 nm would be quenched by cobalt oxyhydroxide (CoOOH) nanoflakes. -phenylenediamine (OPD) would be oxidized to 2,3-diaminophenazine (DAP) by CoOOH nanoflakes that have peroxidase-like activity, which produces a new fluorescent peak at 556 nm. Meanwhile, SiNPs' fluorescence would be quenched through DAP due to inner filter effect (IFE). With the addition of GA, the reductive decomposition of CoOOH decreased DAP level, causing IFE being restrained. The concentration of GA indicates an excellent linear relationship with fluorescence ratio (F/F) in range of 0.4-12 μM (R = 0.9937) with 0.16 μM detection limit. This nanoprobe is applied to GA detection in water, tea leaves, fruits and nut fruits, which would be expected to act as a portable device for complex substances analysis.
没食子酸（GA）作为抗氧化剂被广泛应用于饮料、食品及其他领域。然而，GA具有轻微毒性，其积累对人体有害。因此，开发简单灵敏的GA检测方法至关重要。在本工作中，设计并制备了一种用于检测不同食品中GA的新型比率荧光纳米探针（命名为CoOOH/OPD/SiNPs）。硅纳米颗粒（SiNPs）在443nm处的荧光会被氢氧化氧钴（CoOOH）纳米片淬灭。邻苯二胺（OPD）会被具有过氧化物酶样活性的CoOOH纳米片氧化为2,3-二氨基吩嗪（DAP），在556nm处产生一个新的荧光峰。同时，由于内滤效应（IFE），SiNPs的荧光会通过DAP被淬灭。加入GA后，CoOOH的还原分解降低了DAP水平，导致IFE受到抑制。GA浓度与荧光比率（F/F）在0.4 - 12μM范围内呈现良好的线性关系（R = 0.9937），检测限为0.16μM。该纳米探针应用于水、茶叶、水果和坚果中GA的检测，有望成为一种用于复杂物质分析的便携式设备。
