Enzyme-free electrochemical immunosensor based on methylene blue and the electro-oxidation of hydrazine on Pt nanoparticles.
Enzyme-free electrochemical immunosensor based on methylene blue and the electro-oxidation of hydrazine on Pt nanoparticles.
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DOI：
10.1016/j.bios.2016.10.094
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发表时间：
2017-06-15
影响因子：
12.6
通讯作者：
Lillehoj PB
中科院分区：
文献类型：
--
作者：
Dutta G;Nagarajan S;Lapidus LJ;Lillehoj PB
无酶电化学传感器可以实现快速、高灵敏度的测量，而不受与酶报告相关的限制。然而，非酶电化学传感器的性能往往受到电极动力学速度慢和信号稳定性差的影响。我们报道了一种新的无酶电化学免疫传感器，该传感器基于一种独特的竞争检测方案，该方案使用亚甲基蓝(MB)、肼和铂纳米颗粒(铂纳米颗粒)。该方案与使用MB标记的检测抗体作为非酶报告的强健免疫夹心格式相结合。在靶抗原存在的情况下，表面固定的MB消耗界面上的联氨，从而减少联氨在铂纳米颗粒上的电氧化。因此，抗原的浓度与电化学信号的减少成正比。为了验证概念，该传感器被用于检测未掺杂的人类唾液样本中的恶性疟原虫富含组氨酸蛋白2(PfHRP2)，这是一种重要的疟疾生物标志物。计时库仑测量表明，该平台具有PM范围的灵敏度、高特异度和良好的重复性，非常适合于包括非侵入性诊断测试在内的许多生物传感应用。
Enzyme-free electrochemical sensors enable rapid, high sensitivity measurements without the limitations associated with enzyme reporters. However, the performance of non-enzymatic electrochemical sensors tends to suffer from slow electrode kinetics and poor signal stability. We report a new enzyme-free electrochemical immunosensor based on a unique competitive detection scheme using methylene blue (MB), hydrazine and platinum nanoparticles (Pt NPs). This scheme is coupled with a robust immunosandwich format employing a MB-labelled detection antibody as a non-enzymatic reporter. In the presence of the target antigen, surface-immobilized MB consumes interfacial hydrazine thereby diminishing the electro-oxidation of hydrazine on Pt NPs. Thus, the concentration of the antigen is directly proportional to the reduction in the electrochemical signal. For proof-of-concept, this sensor was used to detect Plasmodium falciparum histidine-rich protein 2 (PfHRP2), an important malaria biomarker, in unadulterated human saliva samples. Chronocoulometric measurements showed that this platform exhibits pM-range sensitivity, high specificity and good reproducibility, making it well suited for many biosensing applications including noninvasive diagnostic testing.