DNAzyme-functionalized gold-palladium hybrid nanostructures for triple signal amplification of impedimetric immunosensor
DNAzyme-functionalized gold-palladium hybrid nanostructures for triple signal amplification of impedimetric immunosensor
复制标题
DNA酶功能化金-钯杂化纳米结构，用于阻抗免疫传感器的三重信号放大。
DOI：
10.1016/j.bios.2013.11.014
复制
发表时间：
2014-04-15
影响因子：
12.6
通讯作者：
Tang, Dianping
中科院分区：
文献类型：
--
作者：
Hou, Li;Gao, Zhuangqiang;Tang, Dianping
利用抗前列腺特异性抗原（PSA）抗体和DNA酶功能化的金钯杂化纳米标签（Ab（2）-AuPd-DNA），设计了一种具有三重信号放大功能的高灵敏度、高选择性阻抗免疫传感器，用于PSA的超灵敏检测。基于Ab（2）-AuPd-DNA的催化沉淀4-氯-1-萘酚（4-CN）的信号被放大。DNAzyme作为一种过氧化物酶模拟物，可以催化4-CN的氧化，而AuPd杂化纳米结构不仅可以提供大的表面覆盖率，用于固定生物分子，而且在一定程度上促进4-CN的氧化。生成的不溶性苯并-4-氯己二烯酮通过4-CN包覆在电极表面，阻碍了溶液与电极之间的电子传递，从而增加了基底电极的法拉第阻抗。本文研究了Ab（2）-AuNP、Ab（2）-AuPd和Ab（2）-AuPd-DNA三种标记方法对PSA的测定，其中Ab（2）-AuPd-DNA标记方法获得了较好的分析性能。在最佳条件下，该阻抗免疫传感器的动态浓度范围为1.0 ~ 50 ng/mL PSA，检测限为0.73 pg/mL。批内和批间变异系数分别低于8.5%和9.5%。重要的是，在6份临床血清标本和6份稀释标准品的分析中，阻抗免疫传感器和用于PSA检测的商业化电化学发光方法之间在0.05显著性水平下未出现显著差异。(C)2013 Elsevier B. V.保留所有权利。
A highly sensitive and selective impedimetric immunosensor with triple signal amplification was designed for ultrasensitive detection of prostate-specific antigen (PSA) by using anti-PSA antibody and DNAzyme-functionalized gold-palladium hybrid nanotags (Ab(2)-AuPd-DNA). The signal was amplified based on the Ab(2)-AuPd-DNA toward the catalytic precipitation of 4-choloro-1-naphthol (4-CN). DNAzyme (as a kind of peroxidase mimic) could catalyze the oxidation of 4-CN, whilst AuPd hybrid nanostructures could not only provide a large surface coverage for immobilization of biomolecules but also promote 4-CN oxidation to some extent. The produced insoluble benzo-4-chlorohexadienone via 4-CN was coated on the electrode surface, and hindered the electron transfer between the solution and the electrode, thereby increasing the Faradaic impedance of the base electrode. Three labeling strategies including Ab(2)-AuNP, Ab(2)-AuPd and Ab(2)-AuPd-DNA were investigated for determination of PSA, and improved analytical features were obtained with the Ab(2)-AuPd-DNA strategy. Under optimal conditions, the dynamic concentration range of the impedimetric immunosensor spanned from 1.0 pg mL(-1) to 50 ng mL(-1) PSA with a detection limit of 0.73 pg mL(-1). Intra- and inter-assay coefficients of variation were below 8.5% and 9.5%, respectively. Importantly, no significant differences at the 0.05 significance level were encountered in the analysis of 6 clinical serum specimens and 6 diluted standards between the impedimetric immunosensor and the commercialized electrochemiluminescent method for PSA detection. (C) 2013 Elsevier B.V. All rights reserved.