Tang Xiaodi, Yin Zhengzhi, Lei Xiaoling, Zeng Yanbo, Zhang Zulei, Lu Yixia, Zhou Guobao, Li Lei, Wu Xiaohua
College of Chemistry and Life Science, Zhejiang Normal University, Jinhua 321004, China.
College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, China.
Nanomaterials (Basel). 2019 Mar 2;9(3):332. doi: 10.3390/nano9030332.
A novel, facile sensor was further developed for microcystin-LR (MC-LR) determination by visible spectroscopy. Antibody-functionalized SiO₂-coated magnetic nanoparticles (Fe₃O₄@SiO₂) and aptamer-functionalized polydopamine nanospheres decorated with Cu nanoparticles (PDA/CuNPs) recognized specific sites in MC-LR and then the sandwich-type composites were separated magnetically. The Cu in the separated composites was converted to Cu ions in solution and turn-on visible absorption was achieved after reaction with bis(cyclohexanone)oxaldihydrazone (BCO) ( = 600 nm). There was a quantitative relationship between the spectral intensity and MC-LR concentration. In addition, under the optimum conditions, the sensor turns out to be a linear relationship from 0.05 to 25 nM, with a limit of detection of 0.05 nM (0.05 μg/L) (/ = 3) for MC-LR. The sensitivity was dependent on the low background absorption from the off-to-on spectrum and label amplification by the polydopamine (PDA) surface. The sensor had high selectivity, which shows the importance of dual-site recognition by the aptamer and antibody and the highly specific color formed by BCO with Cu. The bioassay was complete within 150 min, which enabled quick determination. The sensor was successfully used with real spiked samples. These results suggest it has potential applications in visible detection and could be used to detect other microcystin analogs.
通过可见光谱法进一步开发了一种新颖、简便的微囊藻毒素-LR（MC-LR）检测传感器。抗体功能化的二氧化硅包覆磁性纳米颗粒（Fe₃O₄@SiO₂）和用铜纳米颗粒修饰的适体功能化聚多巴胺纳米球（PDA/CuNPs）识别MC-LR中的特定位点，然后通过磁性分离夹心型复合材料。分离出的复合材料中的铜转化为溶液中的铜离子，与双（环己酮）草酰二腙（BCO）（λ = 600 nm）反应后实现开启型可见吸收。光谱强度与MC-LR浓度之间存在定量关系。此外，在最佳条件下，该传感器对MC-LR的线性范围为0.05至25 nM，检测限为0.05 nM（0.05 μg/L）（n = 3）。灵敏度取决于从关闭到开启光谱的低背景吸收以及聚多巴胺（PDA）表面的标记放大。该传感器具有高选择性，这表明适体和抗体的双位点识别以及BCO与铜形成的高特异性颜色的重要性。生物测定在150分钟内完成，实现了快速检测。该传感器已成功用于实际加标样品。这些结果表明它在可见检测方面具有潜在应用，可用于检测其他微囊藻毒素类似物。
