State Key Laboratory of Electroanalytical Chemistry, c/o Engineering Laboratory for Modern Analytical Techniques, Changchun Institute of Applied Chemistry , Chinese Academy of Sciences , Changchun 130022 , China.
University of Science and Technology of China , Hefei 230026 , China.
Anal Chem. 2019 Aug 20;91(16):10657-10662. doi: 10.1021/acs.analchem.9b01889. Epub 2019 Jun 27.
Propyl gallate (PG) as one of the important synthetic antioxidants is widely used in the prevention of oxidative deterioration of oils during processing and storage. Determination of PG has received extensive concern because of its possible toxic effects on human health. Herein, we report a photoelectrochemical (PEC) sensor based on ZnO nanorods and MoS flakes with a vertically constructed p-n heterojunction. In this system, the n-type ZnO and p-type MoS heterostructures exhibited much better optoelectronic behaviors than their individual materials. Under an open circuit potential (zero potential) and visible light excitation (470 nm), the PEC sensor exhibited extraordinary response for PG determination, as well as excellent anti-inference properties and good reproducibility. The PEC sensor showed a wide linear range from 1.25 × 10 to 1.47 × 10 mol L with a detection limit as low as 1.2 × 10 mol L. MoS/ZnO heterostructure with proper band level between MoS and ZnO could make the photogenerated electrons and holes separated more easily, which eventually results in great improvement of sensitivity. On the other hand, formation of a five membered chelating ring structure of Zn(II) with adjacent oxygen atoms of PG played significant roles for selective detection of PG. Moreover, the PEC sensor was successfully used for PG analysis in different samples of edible oils. It demonstrated the ability and reliability of the MoS/ZnO-based PEC sensor for PG detection in real samples, which is beneficial for food quality monitoring and reducing the risk of overuse of PG in foods.
没食子酸丙酯（PG）作为一种重要的合成抗氧化剂，广泛应用于油脂加工和储存过程中防止氧化变质。由于其对人体健康可能产生的毒性影响，PG 的测定受到了广泛关注。本文报道了一种基于 ZnO 纳米棒和 MoS 薄片的光电化学（PEC）传感器，具有垂直构建的 p-n 异质结。在该体系中，n 型 ZnO 和 p 型 MoS 异质结构表现出比其各自材料更好的光电行为。在开路电位（零电位）和可见光激发（470nm）下，PEC 传感器对 PG 的测定表现出非凡的响应，以及优异的抗干扰性能和良好的重现性。PEC 传感器显示出从 1.25×10到 1.47×10mol/L 的宽线性范围，检测限低至 1.2×10mol/L。MoS/ZnO 异质结构具有 MoS 和 ZnO 之间适当的能带水平，可以使光生电子和空穴更容易分离，从而最终大大提高了灵敏度。另一方面，PG 中相邻氧原子与 Zn(II)形成五元螯合环结构，对 PG 的选择性检测起着重要作用。此外，该 PEC 传感器成功地用于不同食用油样品中的 PG 分析。它证明了基于 MoS/ZnO 的 PEC 传感器在实际样品中检测 PG 的能力和可靠性，这有利于食品质量监测，减少 PG 在食品中过度使用的风险。
