A Photoelectrochemical Immunosensor Based on Au-Doped TiO2 Nanotube Arrays for the Detection of α-Synuclein
A Photoelectrochemical Immunosensor Based on Au-Doped TiO2 Nanotube Arrays for the Detection of α-Synuclein
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DOI：
10.1002/chem.201001654
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发表时间：
2010-01-01
影响因子：
4.3
通讯作者：
Zhang, Wen
中科院分区：
文献类型：
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作者：
An, Yarui;Tang, Linlin;Zhang, Wen
α-突触核蛋白（alpha-Synuclein，alpha-SYN）是一种重要的神经元蛋白，与帕金森病有关。本文利用Au掺杂TiO 2纳米管阵列设计了一种检测α-SYN的光电化学免疫传感器。采用电化学阳极氧化技术在纯钛片上制备了高度有序的TiO 2纳米管。在此之后，光电化学沉积方法被利用来修改所得到的纳米管与Au纳米粒子，这已被证明有助于改善光电流响应。此外，Au掺杂的TiO 2纳米管形成有效的抗体固定阵列，并固定具有高稳定性和生物活性的一抗（Ab（1））以结合靶a-SYN。通过使用{Ab（2）-Au-GOx}生物缀合物获得增强的灵敏度，其特征在于二抗（Ab（2））和葡萄糖氧化酶（GOx）标记物连接到Au纳米颗粒用于信号放大。将GOx酶固定在免疫传感器上，可以催化检测溶液中的葡萄糖产生H2 O2，H2 O2作为牺牲电子供体，在Ti箔的另一面照射时，将TiO 2纳米管价带中的光生空穴吸收，产生快速光电流。该传感器的线性范围为50 pgmL（-1）~ 100 ngmL（-1），检测限为34 pgmL（-1）。该方法具有灵敏度高、稳定性好、重复性好等特点，有望成为一种有前途的蛋白质检测技术。
alpha-Synuclein (alpha-SYN) is a very important neuronal protein that is associated with Parkinson's disease. In this paper, we utilized Au-doped TiO2 nanotube arrays to design a photoelectrochemical immunosensor for the detection of alpha-SYN. The highly ordered TiO2 nanotubes were fabricated by using an electrochemical anodization technique on pure Ti foil. After that, a photoelectrochemical deposition method was exploited to modify the resulting nanotubes with Au nanoparticles, which have been demonstrated to facilitate the improvement of photocurrent responses. Moreover, the Au-doped TiO2 nanotubes formed effective antibody immobilization arrays and immobilized primary antibodies (Ab(1)) with high stability and bioactivity to bind target alpha-SYN. The enhanced sensitivity was obtained by using {Ab(2)-Au-GOx} bioconjugates, which featured secondary antibody (Ab(2)) and glucose oxidase (GOx) labels linked to Au nanoparticles for signal amplification. The GOx enzyme immobilized on the prepared immunosensor could catalyze glucose in the detection solution to produce H2O2, which acted as a sacrificial electron donor to scavenge the photogenerated holes in the valence band of TiO2 nanotubes upon irradiation of the other side of the Ti foil and led to a prompt photocurrent. The photocurrents were proportional to the alpha-SYN concentrations, and the linear range of the developed immunosensor was from 50 pgmL(-1) to 100 ngmL(-1) with a detection limit of 34 pgmL(-1). The proposed method showed high sensitivity, stability, reproducibility, and could become a promising technique for protein detection.