Porous Gold Nanocages: High Atom Utilization for Thiolated Aptamer Immobilization to Well Balance the Simplicity, Sensitivity, and Cost of Disposable Aptasensors
Porous Gold Nanocages: High Atom Utilization for Thiolated Aptamer Immobilization to Well Balance the Simplicity, Sensitivity, and Cost of Disposable Aptasensors
复制标题
多孔金纳米笼：硫醇适体固定的高原子利用率，可很好地平衡一次性适体传感器的简单性、灵敏度和成本
DOI：
10.1021/acs.analchem.9b02145
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发表时间：
2019-07-02
影响因子：
7.4
通讯作者：
Wang, Kun
中科院分区：
文献类型：
--
作者：
An, Keqi;Lu, Xiaoting;Wang, Kun
金纳米结构如纳米球、纳米棒或纳米线已被广泛用于电极表面修饰，因为它们不仅可以增加整体电活性表面，而且还可以通过容易的Au-S共价键为硫醇化适体提供锚定位点。然而，所有这些使用的金纳米结构都是固体，只有外表面是有吸引力的。为了减少贵金属金的使用，本文将具有内外壁的多孔金纳米笼（AuNCs）静电吸附在丝网印刷碳电极（SPCE）上，制备了一种真正无标记的高灵敏度适体传感器。具体而言，选择对黄曲霉毒素B1（AFB 1）具有特异性的硫醇化适体作为模型适体，并使用Au-S化学将其共价结合到AuNCs的内表面和外表面。将感测界面暴露于靶标可以引发适体/靶标复合物的形成，从而导致SPCE上的界面电子转移阻力增加。在最佳条件下，该传感器对黄曲霉毒素B1的检测范围为0.1 pg mL（-1）~ 100 ng mL（-1），线性拟合良好，检测限为0.03 pg mL（-1）（S/N = 3）。该适体传感器具有操作简单、成本低、灵敏度高、试剂用量少等优点。因此，我们提供了一种通用策略，以很好地平衡具有特异性适体链的大量靶标的一次性适体传感器的简单性、灵敏度和成本。
Gold nanostructures such as nanospheres, nanorods, or nanowires have been extensively used for electrode surface modification because they not only can increase the overall electroactive surface but can also provide anchoring sites for thiolated aptamers through facile Au-S covalent bonds. However, all of those gold nanostructures used are solid and only the outer surface is attractive. In the aim to reduce the usage of precious gold, in this paper, porous gold nanocages (AuNCs) with both inner and outer walls for effective aptamer immobilization have been electrostatically adhered on a screen-printed carbon electrode (SPCE), to develop a highly sensitive aptasensor in a truly label-free manner. Specifically, the thiolated aptamers specific for aflatoxin B1 (AFB1) were chosen as the model aptamer and covalently bound to the inner and outer surface of AuNCs using Au-S chemistry. Exposing the sensing interface to targets could initiate the formation of the aptamer/target complex, resulting in an increased interfacial electron transfer resistance on the SPCE. Under optimal conditions, this aptasensor could detect AFB1 in a wide range of 0.1 pg mL(-1) to 100 ng mL(-1) with a high linear fit and has an ultralow detection limit of 0.03 pg mL(-1) (S/N = 3). The developed aptasensor has remarkable merits such as simpler operation, more cost-effective, more sensitive, and less reagent consumption. We therefore provided a universal strategy to well balance the simplicity, sensitivity, and cost of disposable aptasensors for a large population of targets having specific aptamer strands.