Quenching of the emission of peroxydisulfate system by ferrocene functionalized chitosan nanoparticles: A sensitive “signal off” electrochemiluminescence immunosensor
Quenching of the emission of peroxydisulfate system by ferrocene functionalized chitosan nanoparticles: A sensitive “signal off” electrochemiluminescence immunosensor
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DOI：
10.1016/j.snb.2013.11.032
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发表时间：
2014-03
影响因子：
8.4
通讯作者：
Ying Zhuo;Jing Han;L. Tang;Ni Liao;Guofeng Gui;Y. Chai;R. Yuan
中科院分区：
文献类型：
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作者：
Ying Zhuo;Jing Han;L. Tang;Ni Liao;Guofeng Gui;Y. Chai;R. Yuan
首次以二茂铁功能化壳聚糖纳米颗粒(FC-CsNPs)为标记，构建了一种新型灵敏的“信号关闭”电化学发光(ECL)免疫传感器，用于猝灭过二硫酸盐体系的发光。本论文采用反离子络合物凝聚法制备了CsNPs，并通过共价交联法将多个Fc抗体和检测抗体(Ab2)固定在一起。将羧基聚酰胺(PAMAM)树枝状大分子组装到牛血清白蛋白(BSA)修饰电极上，构建了传感平台。其中，BSA层提供了一个多功能的界面，具有良好的生物相容性和足够的活性中心来生成与PAMAM的偶联物。因此，PAMAM既可以作为载体固定众多的捕获抗体，又可以作为增强剂显著提高过氧二硫酸盐体系的ECL，从而大大提高免疫传感器的灵敏度。在夹心型免疫反应后，观察到由于Fc-CsNPs标记的Ab2对过二硫酸盐的ECL猝灭，ECL信号显著减弱。结果表明，在0.001-2npg/m L范围内，电致发光强度变化的对数与N-末端前-B型利钠肽浓度的对数成正比，检出限为0.33fg/m L(S/N=0.3)。
In this paper, a novel sensitive “signal off” electrochemiluminescence (ECL) immunosensor was constructed by ferrocene functionalized chitosan nanoparticles (Fc-CsNPs) as tag for quenching peroxydisulfate system emission for the first time. Herein, CsNPs were prepared by a facile counterion complex coacervation method, and then numerous Fc and detection antibodies (Ab2) were immobilized together via covalent cross-linking. The sensing platform was constructed by assembling carboxyl polyamidoamine (PAMAM) dendrimers onto bovine serum albumin (BSA) modified electrode. Herein, BSA layer provided a multifunctional interface with good biocompatibility and sufficient active sites to produce conjugates with PAMAM. Then, PAMAM may play dual roles that not only as carriers to immobilize numerous capture antibodies but also as enhancer to significantly increase the ECL of peroxydisulfate system, thus, greatly improving the immunosensors’ sensitivity. After a sandwich-type immunoreaction, a remarkable decrease of ECL signal was observed due to the ECL quenching of peroxydisulfate by Fc-CsNPs labeled Ab2. As a result, the logarithm of change of ECL intensity has a direct relationship with the logarithm of N-terminal pro-B-type natriuretic peptide concentration in the range of 0.001–2 pg/mL with a detection limit of 0.33 fg/mL (S/N = 3).