Department of Chemistry and Materials Science, Jiangsu Key Laboratory of Green Synthesis for Functional Materials , Jiangsu Normal University , Xuzhou , Jiangsu 221116 , P.R. China.
Department of Chemistry, Waterloo Institute for Nanotechnology , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada.
Anal Chem. 2019 Aug 20;91(16):10887-10893. doi: 10.1021/acs.analchem.9b02789. Epub 2019 Aug 6.
An arsenic-binding aptamer named Ars-3 was reported in 2009, and it has been used for detection of As(III) in more than two dozen papers. In this work, we performed extensive binding assays using isothermal titration calorimetry, various DNA-staining dyes, and gold nanoparticles. By carefully comparing Ars-3 and a few random control DNA sequences, no specific binding of As(III) was observed in each case. Therefore, we conclude that Ars-3 cannot bind As(III). Possible reasons for some of the previously reported binding and detection were speculated to be related to the adsorption of As(III) onto gold surfaces, which were used in many related sensor designs, and As(III)/Au interactions were not considered before. The selection data in the original paper were then analyzed in terms of sequence alignment, secondary structure prediction, and dissociation constant measurement. These steps need rigorous testing before confirming specific binding of newly selected aptamers. This study calls for attention to the gap between aptamer selection and biosensor design, and the gap needs to be filled by careful binding assays to further the growth of the aptamer field.
2009 年报道了一种名为 Ars-3 的砷结合适体，此后已有二十多篇论文将其用于检测 As(III)。在这项工作中，我们使用等温滴定量热法、各种 DNA 染色染料和金纳米粒子进行了广泛的结合实验。通过仔细比较 Ars-3 和一些随机对照 DNA 序列，在每种情况下都没有观察到 As(III)的特异性结合。因此，我们得出结论，Ars-3 不能结合 As(III)。推测以前一些报道的结合和检测的可能原因与 As(III)在许多相关传感器设计中使用的金表面上的吸附有关，而之前没有考虑到 As(III)/Au 相互作用。然后根据序列比对、二级结构预测和离解常数测量分析原始论文中的选择数据。在确认新选择的适体的特异性结合之前，这些步骤需要进行严格的测试。这项研究呼吁关注适体选择和生物传感器设计之间的差距，需要通过仔细的结合实验来填补这一差距，以促进适体领域的发展。
