Dual-Aptamer-Based Biosensing of Toxoplasma Antibody

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• 作者：Yang Luo ; Xing Liu ; Tianlun Jiang ; Pu Liao ; Weiling Fu
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：September 3, 2013
• 年：2013
• 卷：85
• 期：17
• 页码：8354-8360
• 全文大小：344K
• 年卷期：v.85,no.17(September 3, 2013)
• ISSN：1520-6882

文摘

A panel of seven aptamers to antitoxoplasma IgG is first discovered in this report. The aptamers are selected using systematic evolution of ligands by exponential enrichment (SELEX) technology, cloned, and identified by sequencing and affinity assay. Among them, two aptamers (TGA6 and TGA7) with the highest affinities are employed as capture probe and detection probe in developing a quantum dots-labeled dual aptasensor (Q-DAS). In the presence of antitoxoplasma IgG, an aptamer鈥損rotein鈥揳ptamer sandwich complex (TGA6鈥揑gG鈥揟GA7) is formed and captured on a multiwell microplate, whose fluorescence can be read out using quantum dots as the fluorescence label, ensuring highly sensitive and specific sensing of antitoxoplasma IgG. The operating characteristics of the proposed assay are guaranteed using dual aptamers as the recognizing probes when compared with antibody-based immunoassay. Q-DAS has a linearity within the range of 0.5鈥?00 IU with a lowest detection of 0.1 IU. Receiver operating curves of 212 clinical samples show a 94.8% sensitivity and 95.7% specificity when the cutoff value is set as 6.5 IU, indicating the proposed Q-DAS is a promising assay in large-scale screening of toxoplasmosis.