Quantum dots based electrochemiluminescent immunosensor by coupling enzymatic amplification for ultrasensitive detection of clenbuterol.
Quantum dots based electrochemiluminescent immunosensor by coupling enzymatic amplification for ultrasensitive detection of clenbuterol.
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DOI：
10.1016/j.aca.2013.08.029
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发表时间：
2013-10
影响因子：
6.2
通讯作者：
Xun Yao;Panpan Yan;Qinghui Tang;Anping Deng;Jianguo Li
中科院分区：
文献类型：
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作者：
Xun Yao;Panpan Yan;Qinghui Tang;Anping Deng;Jianguo Li
设计了一种基于CdSe量子点的超灵敏电化学发光免疫传感器，用于克伦特罗的检测。采用逐层法制备了免疫传感器，并利用原子力显微镜（AFM）和电化学阻抗谱（EIS）对传感器进行了表征。在氧饱和的pH = 9.0的Tris-HCl缓冲溶液中，由于溶解氧的电化学还原生成H2 O2，在阴极过程中可以观察到量子点的强烈电化学发光。在形成免疫复合物后，将辣根过氧化物酶标记的第二抗体简单地固定在电极表面上。由于免疫复合物的空间位阻降低了溶解氧的电子传递速度，ECL发射降低，并且还可以通过酶循环消耗自产的共反应物而大大放大。以盐酸克伦特罗为模型分析物，采用竞争免疫分析法测定盐酸克伦特罗的电化学发光强度，在0.05 ng mL− 1 ~ 1000 ng mL−1的范围内进行宽范围的校正，检测下限为0.02 ng mL−1。该免疫传感器具有良好的稳定性和制作重现性。应用于实际样品的检测，结果令人满意。这种免疫传感策略为量子点在ECL生物传感中的应用和残留检测开辟了新的途径。
An ultrasensitive electrochemiluminescence (ECL) immunosensor based on CdSe quantum dots (QDs) has been designed for the detection of clenbuterol. The immunosensor was fabricated by layer by layer and characterized with atomic force microscopic images (AFM) and electrochemical impedance spectra (EIS). In oxygen-saturated pH = 9.0 Tris-HCl buffer, a strong ECL emission of QDs could be observed during the cathodic process due to the H2O2product from electrochemical reduction of dissolved oxygen. Upon the formation of immunocomplex, the second antibody labeled with horseradish peroxidase was simply immobilized on the electrode surface. The ECL emission decreased since steric hindrance of the immunocomplex slowed down the electron-transfer speed of dissolved oxygen, and also could be greatly amplified by an enzymatic cycle to consume the self-produced coreactant. Using clenbuterol as model analyte, the ECL intensity was determined by the concentration of competitive immunoassay of clenbuterol with a wide calibration in the range of 0.05 ng mL−1to 1000 ng mL−1, and a low detection limit was 0.02 ng mL−1. The immunosensor shows good stability and fabrication reproducibility. It was applied to detecting practical samples with the satisfactory results. This immunosensing strategy opens a new avenue for detection of residue and application of QDs in ECL biosensing.