Anodic-stripping voltammetric immunoassay for ultrasensitive detection of low-abundance proteins using quantum dot aggregated hollow microspheres.
Anodic-stripping voltammetric immunoassay for ultrasensitive detection of low-abundance proteins using quantum dot aggregated hollow microspheres.
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DOI：
10.1002/chem.201203131
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发表时间：
2013-02
期刊：
影响因子：
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通讯作者：
Bing Zhang;D. Tang;I. Goryacheva;R. Niessner;D. Knopp
中科院分区：
文献类型：
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作者：
Bing Zhang;D. Tang;I. Goryacheva;R. Niessner;D. Knopp
以CdS量子点（QD）层层组装空心微球（QDHMS）为分子标记物，设计了一种新的检测模型蛋白IgG 1的阳极溶出伏安免疫分析方法。最初，将单克隆抗人IgG 1特异性抗体锚定在无定形磁珠上，优选选择性地从样品中捕获IgG 1分析物的F（ab）。为了检测，将单克隆抗人IgG 1（F（c）特异性）抗体与合成的QDHMS共价偶联。在一个快速型免疫分析格式，随后的阳极溶出伏安检测镉释放在酸性条件下从耦合量子点进行原位制备的汞膜电极。该免疫分析将高效的磁性分离与多层QD标记的信号放大相结合。动态浓度范围为1.0 fg mL（-1）至1.0 μg mL（-1），检测限为0.1 fg mL（-1）。电化学免疫分析法具有良好的重现性、选择性和稳定性。临床血清标本的分析显示良好的符合酶联免疫吸附试验方法获得的结果。这种新的免疫分析方法有望用于低丰度生物标志物的无酶和成本效益分析。
A new anodic-stripping voltammetric immunoassay protocol for detection of IgG1, as a model protein, was designed by using CdS quantum dot (QD) layer-by-layer assembled hollow microspheres (QDHMS) as molecular tags. Initially, monoclonal anti-human IgG1 specific antibodies were anchored on amorphous magnetic beads preferably selective to capture F(ab) of IgG1 analyte from the sample. For detection, monoclonal anti-human IgG1 (F(c)-specific) antibodies were covalently coupled to the synthesized QDHMS. In a sandwich-type immunoassay format, subsequent anodic-stripping voltammetric detection of cadmium released under acidic conditions from the coupled QDs was conducted at an in situ prepared mercury film electrode. The immunoassay combines highly efficient magnetic separation with signal amplification by the multilayered QD labels. The dynamic concentration range spanned from 1.0 fg mL(-1) to 1.0 μg mL(-1) of IgG1 with a detection limit of 0.1 fg mL(-1). The electrochemical immunoassay showed good reproducibility, selectivity, and stability. The analysis of clinical serum specimens revealed good accordance with the results obtained by an enzyme-linked immunosorbent assay method. The new immunoassay is promising for enzyme-free, and cost-effective analysis of low-abundance biomarkers.