School of Food Science & Technology, State Key Lab of Food Science & Technology, Jiangnan University, Wuxi 214122, China.
Biosens Bioelectron. 2011 Jul 15;26(11):4393-8. doi: 10.1016/j.bios.2011.04.047. Epub 2011 May 6.
In this paper, we demonstrate the application of versatile G-quadruplex-hemin DNAzymes in an immunoassay for detecting Microcystin-LR (MC-LR). Taking advantage of the high peroxidase activity of G-quadruplex-hemin complexes and the enhancement effect of gold nanoparticles (AuNPs), the method showed simple, high sensitive and selectivity detection of target toxin residues in water samples. The coated antigen, MC-LR-ovalbumin (OVA) coated on a plate, competed for MC-LR antibody with added target analyte to form antibody-antigen immune complexes. Subsequently, the immune complex reacted with G-quadruplex-labeled secondary antibodies for colorimetric detection of MC-LR. This assay specifically determined MC-LR in the linear range of 0.1-10 ng/ml, with a limit of detection (LOD) of 0.05 ng/mL for MC-LR. The results indicated that the novel immunoassay was an alternative to traditional plate-based immunoassay for MC-LR residue screening due to this method met the standard of World Health Organization (WHO) requirements for MC-LR content in drinking water (1 ng/mL).
在本文中，我们展示了多功能 G-四链体-血红素 DNA 酶在用于检测微囊藻毒素-LR（MC-LR）的免疫测定中的应用。利用 G-四链体-血红素复合物的高过氧化物酶活性和金纳米粒子（AuNPs）的增强效应，该方法显示了对水样中目标毒素残留的简单、高灵敏和选择性检测。包被抗原，即 MC-LR-卵清蛋白（OVA）包被在平板上，与添加的目标分析物竞争 MC-LR 抗体，形成抗体-抗原免疫复合物。随后，免疫复合物与 G-四链体标记的二级抗体反应，进行 MC-LR 的比色检测。该测定法在 0.1-10ng/ml 的线性范围内特异性地确定了 MC-LR，MC-LR 的检测限（LOD）为 0.05ng/mL。结果表明，由于该方法符合世界卫生组织（WHO）对饮用水中 MC-LR 含量（1ng/mL）的要求，因此新型免疫测定法是传统平板免疫测定法用于 MC-LR 残留筛选的替代方法。
