Ultrasensitive electrochemical strategy for trace detection of APE-1 via triple signal amplification strategy.
Ultrasensitive electrochemical strategy for trace detection of APE-1 via triple signal amplification strategy.
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DOI：
10.1016/j.bios.2012.07.082
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发表时间：
2013-03
影响因子：
12.6
通讯作者：
Jing Han;Ying Zhuo;Y. Chai;Yun Xiang;R. Yuan;Yali Yuan;Ni Liao
中科院分区：
文献类型：
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作者：
Jing Han;Ying Zhuo;Y. Chai;Yun Xiang;R. Yuan;Yali Yuan;Ni Liao
本文报道了一种新的三步信号放大电化学免疫分析法测定脱嘌呤/脱嘧啶核酸内切酶（APE-1）。第一步信号放大过程是基于六氰合铁酸镍纳米颗粒修饰的Au纳米链（Ni-AuNCs）上标记的生物素化碱性磷酸酶（bio-AP）对抗坏血酸2-磷酸（AA-P）的生物催化原位产生抗坏血酸（AA）。然后，由于Ni-AuNCs的催化作用，原位产生的AA的电化学氧化进一步放大了信号。最后，利用纳米链修饰的链霉亲和素（SA），可以通过链霉亲和素-生物素的特异性和高亲和力相互作用来增加生物AP的化学计量。另一方面，一种有机材料（PTC-NH 2）由于其氨基功能化的界面和独特的电化学性质，作为一抗（Ab 1）的固定化基质，可以降低背景电流信号，提高Ab 1的固定量。由于APE-1具有免疫反应性，三重信号放大大大提高了检测APE-1的灵敏度。在最佳条件下，该电化学免疫传感器的线性范围为0.01- 100 pg/mL，检测限为3.9fg/mL（信噪比=3）。
A novel ultrasensitive electrochemical immunoassay for the determination of apurinic/apyrimidinic endonuclease (APE-1) using a three-step signal amplification process was reported in this work. The first-step signal amplification process was based on the labeled biotinylated alkaline phosphatase (bio-AP) on the nickel hexacyanoferrates nanoparticle-decorated Au nanochains (Ni–AuNCs) toward the biocatalysis of ascorbic acid 2-phosphate (AA-P) to in-situ produce ascorbic acid (AA). Then the signal was further amplified by electrochemical oxidation of the in-situ-produced AA because of the catalysis of Ni–AuNCs. Finally, with the nanochain-modified streptavidin (SA), the stoichiometry of bio-AP could be increased through the specific and high affinity interaction of streptavidin–biotin. On the other hand, a kind of organic material (PTC-NH2), owing the amino-functionalized interface and unique electrochemical properties, as matrix for primary antibodies (Ab1) immobilization could lower the background current signal and enhance the amount of immobilized Ab1. With a sandwich-type immunoreaction, the triple signal amplification greatly enhanced the sensitivity for the detection of APE-1. Under optimal conditions, the electrochemical immunosensor exhibited a linear range of 0.01–100pg/mL with an extremely low detection limit of 3.9fg/mL (signal/noise=3).