Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062, People's Republic of China.
Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan, People's Republic of China.
Mikrochim Acta. 2024 May 8;191(6):312. doi: 10.1007/s00604-024-06389-y.
Phytosterols (PSs), a class of naturally occurring bioactive lipid compounds, have been found to possess a significant cholesterol-lowering effect. In developing countries, the consumption of rapeseed oil is the primary pathway of PS intake for the general population. However, developing low-cost, real-time, and high-throughput screening techniques for PSs remains a challenge. Here, a Cu-based nanocomposite CuOx@C was synthesized via a simple method of the calcination of HKUST-1 and systematically characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The CuOx@C demonstrated excellent peroxidase-like (POD-like) activity, functioning as a peroxidase mimic to facilitate the catalysis of 3,3',5,5'-tetramethylbenzidine (TMB) into its oxidized form (oxTMB), thereby initiating a discernible color response. On the basis of this discovery, a CuOx@C-based colorimetric method for detecting total sterols in rapeseed was successfully constructed via cascade reactions. After optimizing the conditions, the high-throughput screening of total sterols in rapeseed could be completed in only 21 min, which significantly facilitated the sensing of PSs. A linear range of 0.6-6 mg/g was achieved for the detection of total sterols in rapeseed samples, thereby satisfying the requirements for detection. In addition, due to the high stability of CuOx@C and the specificity of cholesterol oxidase, the developed method had excellent stability and selectivity toward PSs, indicating that this work has huge prospects for commercial application. This innovative work overcomes the limitation of the instrumental method and provides a portable and reliable tool for total sterols detection. It can also facilitate the development of oilseeds with a high content of PSs.
植物甾醇（PSs）是一类天然存在的生物活性脂质化合物，已被发现具有显著的降胆固醇作用。在发展中国家，油菜籽油的消费是一般人群摄入 PSs 的主要途径。然而，开发低成本、实时、高通量的 PSs 筛选技术仍然是一个挑战。在这里，通过 HKUST-1 的煅烧，简单地合成了一种基于铜的纳米复合材料 CuOx@C，并通过扫描电子显微镜、透射电子显微镜、X 射线衍射和 X 射线光电子能谱对其进行了系统地表征。CuOx@C 表现出优异的过氧化物酶样（POD-like）活性，可作为过氧化物酶模拟物，促进 3,3',5,5'-四甲基联苯胺（TMB）转化为其氧化形式（oxTMB），从而引发可识别的颜色响应。基于这一发现，通过级联反应成功构建了一种基于 CuOx@C 的油菜籽总甾醇比色检测方法。在优化条件后，仅需 21 分钟即可完成油菜籽中总甾醇的高通量筛选，从而显著促进了 PSs 的检测。油菜籽样品中总甾醇的检测线性范围为 0.6-6mg/g，满足检测要求。此外，由于 CuOx@C 的高稳定性和胆固醇氧化酶的特异性，该方法对 PSs 具有优异的稳定性和选择性，表明该工作具有巨大的商业应用前景。这项创新性工作克服了仪器方法的局限性，为总甾醇检测提供了一种便携可靠的工具。它还可以促进高 PSs 含量的油籽的开发。
