School of Pharmacy, Xinjiang Medical University, Xinyi Road, Urumqi 830054, China.
College Life Science & Technology, Xinjiang University, Shengli Road, Urumqi 830046, China.
Biosensors (Basel). 2022 Apr 14;12(4):242. doi: 10.3390/bios12040242.
Residue and illegal addition of Dexamethasone (DEX) in food has received widespread attention over the past few decades. Long-term intake of DEX will have a strong endocrine-disrupting effect, and there is an urgent need to develop highly sensitive and rapid on-site detection methods. In this work, a colorimetric sensor based on an unmodified aptamer and gold nanoparticles (Au NPs) was designed to detect DEX in milk and glucosamine. Under optimized conditions, the absorbance ratio of Au NPs increased linearly with DEX concentration over the range of 10-350 nmol/mL (r = 0.997), with a limit of detection (LOD) of 0.5 nmol/mL, and the recoveries ranged from 93.6 to 117%. To explore the interaction mechanism between aptamer and DEX, molecular docking and molecular dynamics simulations were applied to probe intermolecular interactions and structures of the complex. The establishment of aptamer-based sensors effectively avoids the antibody screening response, with a cost-efficient, excellent selective and great potential in DEX determination.
在过去几十年中，食品中地塞米松（DEX）的残留和非法添加受到了广泛关注。长期摄入 DEX 会产生强烈的内分泌干扰作用，因此迫切需要开发高灵敏度和快速的现场检测方法。在这项工作中，设计了一种基于未经修饰的适体和金纳米粒子（Au NPs）的比色传感器，用于检测牛奶和葡萄糖胺中的 DEX。在优化条件下，Au NPs 的吸光度比值随 DEX 浓度在 10-350 nmol/mL 范围内呈线性增加（r = 0.997），检出限（LOD）为 0.5 nmol/mL，回收率在 93.6%至 117%之间。为了探索适体与 DEX 之间的相互作用机制，应用分子对接和分子动力学模拟来探测分子间相互作用和复合物的结构。基于适体的传感器的建立有效地避免了抗体筛选反应，具有成本效益高、选择性好、在 DEX 测定中具有很大潜力的特点。
