Ultrasensitive Immunoassay of Protein Biomarker Based on Electrochemiluminescent Quenching of Quantum Dots by Hemin Bio-Bar-Coded Nanoparticle Tags
Ultrasensitive Immunoassay of Protein Biomarker Based on Electrochemiluminescent Quenching of Quantum Dots by Hemin Bio-Bar-Coded Nanoparticle Tags
复制标题
基于血红素生物条形码纳米颗粒标签对量子点进行电化学发光猝灭的蛋白质生物标志物超灵敏免疫测定
DOI：
10.1021/ac200398x
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发表时间：
2011-07-01
影响因子：
7.4
通讯作者：
Ju, Huangxian
中科院分区：
文献类型：
--
作者：
Lin, Dajie;Wu, Jie;Ju, Huangxian
通过将抗体与巯基化的G-四链体DNA组装在金纳米粒子上，并与氯化血红素相互作用形成G-四链体/氯化血红素生物条形码，设计了一种氯化血红素生物条形码纳米粒子探针标记抗体。将标记抗体与电致发光免疫传感器结合，建立了一种超灵敏的蛋白质免疫分析方法。电化学发光免疫传感器是由碳纳米管、硫化镉量子点和捕获抗体层层修饰在玻碳电极上制成的。在空气饱和的pH 8.0的PBS中，该免疫传感器显示出碳纳米管增强的阴极ECL发射的量子点。免疫复合物形成后，由于生物条形码电催化还原溶解氧过程中ECL共反应物的消耗，ECL强度下降。以甲胎蛋白为模型分析物，电化学发光法测定甲胎蛋白的线性范围为0.01 ~ 1 ng/mL，检出限为1.0 fg/mL。由于生物条形码的增强ECL发射和高效催化作用，使其具有较宽的检测范围和较高的灵敏度。该免疫传感器具有良好的稳定性和可接受的制作重现性和准确性，显示出良好的临床应用前景。
A hemin bio-bar-coded nanopartide probe labeled antibody was designed by the assembly of antibody and alkylthiol-capped bar-code G-quadruplex DNA on gold nanoparticles and the interaction of hemin with the DNA to form a G-quadruplex/hemin bio-bar-code. An ultrasensitive immunoassay method was developed by combining the labeled antibody with an electrochemiluminescent (ECL) immunosensor for protein. The ECL immunosensor was constructed by a layer-by-layer modification of carbon nanotubes, CdS quantum dots (QDs), and capture antibody on a glassy carbon electrode. In air-saturated pH 8.0 PBS the immunosensor showed a carbon-nanotube-enhanced cathodic ECL emission of QDs. Upon the formation of immunocomplex, the ECL intensity decreased owing to the consumption of ECL coreactant in bio-bar-code electrocatalyzed reduction of dissolved oxygen. Using alpha-fetoprotein as model analyte, the cluenched ECL could be used for immunoassay with a linear range of 0.01 pg mL(-1) to 1 ng mL(-1) and a detection limit of 1.0 fg mL(-1). The wide detection range and high sensitivity resulted from the enhanced ECL emission and highly efficient catalysis of the bio-bar-code. The immunosensor exhibited good stability and acceptable fabrication reproducibility and accuracy, showing great promise for clinical application.