Faculty of Material Science and Chemical Engineering, Ningbo University, Ningbo 315211, China.
Institute of Pharmaceutical Analysis, College of Pharmacy, Jinan University, Guangzhou 510632, China.
J Chromatogr A. 2020 Mar 15;1614:460715. doi: 10.1016/j.chroma.2019.460715. Epub 2019 Nov 16.
It is challenging to greatly increase of the extraction selectivity and efficiency by stir bar sorptive extraction of ultra-trace polychlorinated biphenyls (PCBs) in complex environmental matrix, e.g., soils. To fulfill this purpose, one of the critical works is to prepare some coatings with high selectivity, adsorptive capacity and reusability. It is also important to develop some green, simple methods for preperation the coatings. In this work, a kind of highly efficient and bioactive coating based on hyperbranched aptamer (HB-Apt) was constructed via hybridization chain reaction (HCR). Then, the HB-Apt was coated on a magnetic stir bar and applied to headspace extraction of PCB72 and PCB106 in soils. The core-shell gold magnetic particles (FeO@AuNPs, AuMNPs for short) was employed as the substrate to immobilize the HB-Apt. The extracted PCBs on the stir bar could be easily eluted in ethanol by stirring, and then sampled in gas chromatography-mass spectrometry (GC-MS) for qualification. The ultra-low detection limit (0.003-0.005 ng•g), good linearity (0.01-500 ng•g, R≥0.994) and reproducibility (RSD: 4.58-6.53%) were obtained. Compared with the common aptamer coating, the HB-Apt coating exhibited good selectivity and higher extraction capacity. The results might be related to the fact that there are more aptamer fragments grated on the HB-Apt coating than those of the common aptamer coating. The magnetic stir bar can not only be employed for easy headspace extraction, but also facilitate separation and elution. Moreover, the coating could be recycled for at least 60 times before recoveries of the PCB72 and PCB106 in the spiked samples drop below 90%. All these indicated that the assay is simple, robust, environment friendly and promising for detection of trace PCBs in complex environmental samples.
在复杂的环境基质（例如土壤）中，通过搅拌棒吸附萃取（SBSE）超痕量多氯联苯（PCBs），极大地提高萃取选择性和效率是具有挑战性的。为了实现这一目的，关键工作之一是制备具有高选择性、吸附容量和可重复使用性的涂层。开发一些绿色、简单的方法来制备涂层也是很重要的。在这项工作中，通过杂交链式反应（HCR）构建了一种基于超支化适体（HB-Apt）的高效和生物活性涂层。然后，将 HB-Apt 涂覆在磁力搅拌棒上，并应用于土壤中 PCB72 和 PCB106 的顶空萃取。核壳金磁性纳米粒子（FeO@AuNPs，简称 AuMNPs）被用作固定 HB-Apt 的基质。搅拌棒上萃取的 PCBs 可通过搅拌轻松洗脱于乙醇中，然后用气相色谱-质谱法（GC-MS）取样进行定性分析。该方法获得了超低检测限（0.003-0.005ng·g-1）、良好的线性范围（0.01-500ng·g-1，R≥0.994）和重现性（RSD：4.58-6.53%）。与普通适体涂层相比，HB-Apt 涂层表现出良好的选择性和更高的萃取容量。这可能与 HB-Apt 涂层上接枝的适体片段比普通适体涂层上的更多有关。该磁力搅拌棒不仅可用于方便的顶空萃取，还便于分离和洗脱。此外，在加标样品中 PCB72 和 PCB106 的回收率降至 90%以下之前，该涂层可至少回收 60 次。所有这些表明，该方法简单、稳健、环保，有望用于复杂环境样品中痕量 PCBs 的检测。
