Faculty of Material Science and Chemical Engineering , Ningbo University , Ningbo 31521 , China.
Ningbo Institute of Technology , Zhejiang University ; Ningbo 315100 , China.
ACS Sens. 2019 Aug 23;4(8):2131-2139. doi: 10.1021/acssensors.9b00963. Epub 2019 Aug 14.
The development of multiplex assays to simultaneously monitor multiclass chemical contaminants that commonly coexist in foods, such as heavy metal ions, antibiotics, and estrogen residues, is gaining attention. Here, a microfluidic chip (MC)-based multianalysis method coupled with magnetic encoded aptamer probes was used for simultaneous detection of kanamycin, 17β-estradiol, and lead ion (Pb). Using this innovative strategy, the magnetic bead (MB)-based encoded probes labeled with aptamer hybrid chains were first used to selectively capture multiple targets, followed by generating single-stranded primers. The primers triggered a multibranched hybridization chain reaction (mHCR). Finally, three kinds of complementary strands (C-DNAs) with different lengths were hybridized with the arms of the mHCR products to form three types of multibranched DNA nanostructures. The decrement signals of C-DNAs were employed for qualification of targets. As the signal tags corresponded to different targets, the DNA nanostructures realized "one target for the decrease of massive C-DNAs" to improve sensitivity. The use of MB-based encoded probes could achieve magnetic separation to eliminate interference in the complex. The detection limits of this method were 1.76 × 10 nM (kanamycin), 1.18 × 10 nM (17β-estradiol), and 1.29 × 10 nM (lead ion). Furthermore, the MC platform is reusable and can be used for more than 4000 samples. The assay combining the MC with MB-based encoded probes with multibranched DNA signal tags offers a universal, reusable, and high-throughput detection platform for screening multiclass chemical contaminants in food samples with complex matrices.
同时监测食品中常见共存的多类化学污染物（如重金属离子、抗生素和雌激素残留）的多重分析方法的发展受到关注。在这里，使用基于微流控芯片（MC）的多分析方法结合磁性编码适体探针，用于同时检测卡那霉素、17β-雌二醇和铅离子（Pb）。使用这种创新策略，首先使用基于磁珠（MB）的编码探针标记适体杂交链，以选择性捕获多个靶标，然后生成单链引物。引物触发多分支杂交链式反应（mHCR）。最后，三种具有不同长度的互补链（C-DNA）与 mHCR 产物的臂杂交，形成三种类型的多分支 DNA 纳米结构。C-DNA 的递减信号用于定性目标。由于信号标签对应于不同的目标，因此 DNA 纳米结构实现了“一个目标对应于大量 C-DNA 的减少”，以提高灵敏度。使用基于 MB 的编码探针可以进行磁性分离，以消除复杂样品中的干扰。该方法的检测限分别为 1.76×10 nM（卡那霉素）、1.18×10 nM（17β-雌二醇）和 1.29×10 nM（铅离子）。此外，MC 平台可重复使用，可用于超过 4000 个样本。该方法结合了 MC 与基于 MB 的编码探针和多分支 DNA 信号标签，为筛选复杂基质食品样品中的多类化学污染物提供了一种通用、可重复使用和高通量的检测平台。
