Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211, People's Republic of China.
The Art Institute of Ningbo University, Ningbo, 315211, People's Republic of China.
Mikrochim Acta. 2020 Feb 19;187(3):176. doi: 10.1007/s00604-020-4155-5.
The authors describe a microfluidic chip-based aptasensor platform combined with magnetic tripartite DNA structure-functionalized nanocomposites to achieve simultaneous determination of kanamycin (KANA), aflatoxin M1 (AFM1), and 17β-estradiol (E2) in milk. The two-duplex tripartite DNA nanostructure was first assembled on the surface of magnetic beads. When the aptamer on the probes recognized the specific target, the aptamer-target would be released into the supernatant. The pre-primer@circular DNA template structure initiates rolling circle amplification (RCA) by phi29 polymerase. After magnetic separation, the magnetic nanocomposites were added into a solution containing three different lengths of complementary strands to the RCA products. The number of complementary strands significantly decrease, and this can be quantitated by the microfluidic chip. Further, the employment of magnetic nanocomposites and microfluidic chip not only resolve the complex matrix interference, but also dramatically enhances the determination selectivity and sensitivity. This aptasensor allows for determination of KANA, AFM1, and E2 with limits of detection as low as 0.32 pg mL, 0.95 pg mL, and 6.8 pg mL, respectively. This novel method exhibits the advantages of excellent stability and fast response time (< 3 min on microfluidic chip platform) for simultaneous determination of KANA, AFM1, and E2 in milk samples and ensures food safety. Graphical abstract.
作者描述了一种基于微流控芯片的适体传感器平台，结合磁性三方 DNA 结构功能化纳米复合材料，实现了牛奶中同时测定卡那霉素 (KANA)、黄曲霉毒素 M1 (AFM1) 和 17β-雌二醇 (E2)。双双链三方 DNA 纳米结构首先在磁性珠表面组装。当探针上的适体识别特定目标时，适体-靶标将被释放到上清液中。预引物@圆形 DNA 模板结构通过 phi29 聚合酶启动滚环扩增 (RCA)。磁分离后，将磁性纳米复合材料加入到含有与 RCA 产物互补的三种不同长度链的溶液中。互补链的数量显著减少，这可以通过微流控芯片进行定量。此外，磁性纳米复合材料和微流控芯片的使用不仅解决了复杂基质干扰的问题，而且显著提高了测定的选择性和灵敏度。该适体传感器能够以低至 0.32 pg mL、0.95 pg mL 和 6.8 pg mL 的检测限分别测定 KANA、AFM1 和 E2。该新方法表现出良好的稳定性和快速响应时间（在微流控芯片平台上 < 3 分钟）的优点，可用于同时测定牛奶样品中的 KANA、AFM1 和 E2，确保食品安全。图表摘要。
