Electrochemical immunosensor based on Ag+-dependent CTAB-AuNPs for ultrasensitive detection of sulfamethazine.
Electrochemical immunosensor based on Ag+-dependent CTAB-AuNPs for ultrasensitive detection of sulfamethazine.
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DOI：
10.1016/j.bios.2019.111643
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发表时间：
2019-11
影响因子：
12.6
通讯作者：
Mingyue Yang;Xiangyang Wu;Xialin Hu;Kun Wang;Can Zhang;Eric Gyimah;S. Yakubu;Zhen Zhang
中科院分区：
文献类型：
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作者：
Mingyue Yang;Xiangyang Wu;Xialin Hu;Kun Wang;Can Zhang;Eric Gyimah;S. Yakubu;Zhen Zhang
提出了一种电化学生物传感器，利用改进的放大策略快速检测水生环境中的磺胺乙嗪（作为模型靶点）。在这个竞争性免疫分析中，十六烷基三甲基溴化铵包覆的金纳米颗粒（cab - aunps）被用作信号放大器和电极基质，并包被抗原抗体（Cag-Ab1）特异性结合系统作为目标化合物的识别单元。此外，用树突状纤维纳米二氧化硅（DFNS@AgNPs）修饰银纳米粒子标签，并将其修饰在壳聚糖/单壁碳纳米角（CS/SWCNH）修饰的玻璃碳电极（GCEs）上，提高了电子传递率，增加了表面面积，使更多的涂层抗原被捕获。在酸性条件下，大量结合在aunp表面的Ag+溶解，形成Ag+@CTAB-AuNP复合物，明显提高了过氧化物酶样活性，增强了电流响应。此外，Ab1-Ab2-DFNS共轭关系的破坏使阻抗大大降低，导致电化学信号放大。经参数优化后，该方法具有良好的灵敏度（LOD为0.0655 ng/mL）和良好的准确度（回收率为79.02% ~ 118.39%；CV为3.18% ~ 9.82%），表明该方法在环境中痕量污染物的快速检测中具有很大的潜力。
An electrochemical biosensor was proposed utilizing an improved amplification strategy for the rapid detection of sulfamethazine (as a model target) in aquatic environments. In this competitive immunoassay, cetyltrimethylammonium bromide-capped gold nanoparticles (CTAB-AuNPs) were used as a signal amplifier and electrode matrix and coated with an antigen-antibody (Cag-Ab1) specific binding system as a recognition unit for the target compound. In addition, silver nanoparticle labels were functionalized with dendritic fibrous nanosilica (DFNS@AgNPs) and decorated onto chitosan/single walled carbon nanohorn (CS/SWCNH)-modified glass carbon electrodes (GCEs), which improved the electron transfer rate and increased the surface area, enabling more coating antigens to be captured. Under acidic conditions, massive amounts of the Ag+bound to the surface of the AuNPs dissolved, and consequently, formed Ag+@CTAB-AuNP complexes, which resulted in a distinctly improved peroxidase-like activity and enhanced current response. Furthermore, the destroyed Ab1-Ab2-DFNS conjugation greatly decreased the impedance, bringing about the amplification of the electrochemical signals. After optimization of the parameters, the proposed approach exhibited excellent performance, including good sensitivity (LOD, 0.0655 ng/mL) and satisfactory accuracy (recoveries, 79.02%–118.39%; CV, 3.18%–9.82%), which indicates the great potential of this strategy for the rapid detection of trace pollutants in the environments.