School of Life Sciences, Henan University, Kaifeng 475000, China.
Institute of Biochemistry and Biophysics, University of Tehran, Tehran 1417614418, Iran.
Langmuir. 2024 Oct 1;40(39):20495-20504. doi: 10.1021/acs.langmuir.4c02037. Epub 2024 Sep 17.
Luteolin has various pharmacological properties, including anti-inflammatory, antioxidant, and antitumor characteristics. Due to its potential value in drugs and functional foods, it is important to develop an efficient method for detecting luteolin. In this work, the poor selectivity of existing luteolin nonenzymatic sensors was solved by translating the enzyme-catalyzed reaction from bulk solution to the surface of a horseradish peroxidase (HRP) modified electrode through an electrocatalytic oxidation process. Here, we modified the surface of a glassy carbon electrode (GCE) with metal-organic frameworks (MOFs; ZIF-67 here, abbreviated as ZIF), functional nanomaterials, and HRP and finally covered it with Nafion (NF). In this case, luteolin acts as a hydrogen donor, and the electrode acts as a hydrogen acceptor; the oxidation reaction occurs on the electrode surface. The use of ZIF-67 ensured the conformational stability of HRP to ensure the selectivity and anti-interference property, and SDS-dispersed multiwalled carbon nanotubes (MWCNTs) enhanced the electrode conductivity. The use of NF avoids shedding of the electrode material during the testing process. A UV-vis spectrophotometer was used to study the selectivity of luteolin by HRP and the compatibility between HRP and ZIF. The materials were characterized and analyzed by scanning electron microscopy and transmission electron microscopy. Due to the synergistic effect of these nanomaterials, the linear range of NF/ZIF-HRP/MWCNTs-SDS/GCE was 1.0 × 10 to 6.0 μM, with detection limits of 25.3 nM (S/N = 3). The biosensor showed long-term stability and reproducibility, with a relative standard deviation of 4.2% for the peak current ( = 5). Finally, the biosensor was successfully used to detect luteolin in carrots, celery, and cauliflower.
木犀草素具有多种药理特性，包括抗炎、抗氧化和抗肿瘤特性。由于其在药物和功能性食品中的潜在价值，开发一种高效的木犀草素检测方法非常重要。在这项工作中，通过将酶催化反应从本体溶液转化为辣根过氧化物酶（HRP）修饰电极的表面，通过电催化氧化过程解决了现有木犀草素非酶传感器选择性差的问题。在这里，我们用金属有机骨架（MOFs；这里是 ZIF-67，缩写为 ZIF）、功能纳米材料和 HRP 修饰玻碳电极（GCE）表面，最后用 Nafion（NF）覆盖。在这种情况下，木犀草素充当氢供体，电极充当氢受体；氧化反应发生在电极表面。使用 ZIF-67 确保 HRP 的构象稳定性，以确保选择性和抗干扰性，并且 SDS 分散的多壁碳纳米管（MWCNTs）增强了电极的导电性。使用 NF 避免了在测试过程中电极材料的脱落。使用紫外可见分光光度计通过 HRP 研究木犀草素的选择性和 HRP 与 ZIF 的兼容性。通过扫描电子显微镜和透射电子显微镜对材料进行了表征和分析。由于这些纳米材料的协同作用，NF/ZIF-HRP/MWCNTs-SDS/GCE 的线性范围为 1.0×10 至 6.0 μM，检测限为 25.3 nM（S/N = 3）。该生物传感器表现出长期稳定性和可重复性，峰电流的相对标准偏差为 4.2%（n = 5）。最后，该生物传感器成功用于检测胡萝卜、芹菜和花椰菜中的木犀草素。
