Sensing Adenosine and ATP by Aptamers and Gold Nanoparticles: Opposite Trends of Color Change from Domination of Target Adsorption Instead of Aptamer Binding
Sensing Adenosine and ATP by Aptamers and Gold Nanoparticles: Opposite Trends of Color Change from Domination of Target Adsorption Instead of Aptamer Binding
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通过适体和金纳米颗粒感测腺苷和 ATP：目标吸附占主导地位而不是适体结合导致颜色变化的相反趋势
DOI：
10.1021/acssensors.0c01169
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发表时间：
2020
期刊：
影响因子：
8.9
通讯作者：
Juewen Liu
中科院分区：
文献类型：
--
作者：
Fang Zhang;Po-Jung Jimmy Huang;Juewen Liu
腺苷和5′-三磷酸腺苷（ATP）的27聚体DNA适配子是设计生物传感器的常用模型系统。已经报道了使用金纳米颗粒（AuNPs）进行无标记比色检测的各种策略。一般认为，游离的适体可以保护金纳米颗粒免受盐诱导的聚集，而靶结合的适体不能。然而，这些研究仅考虑了适体与其靶标的结合，以及适体在金纳米颗粒上的吸附，而没有考虑金纳米颗粒对靶标分子的吸附。我们在此报道了腺苷的吸附使柠檬酸盐封端的AuNPs不稳定，其表观Kd仅为7.7 μM腺苷，而ATP的吸附由于三磷酸基团的负电荷而使AuNPs稳定。吸附的ATP抑制DNA的吸附。使用适配体和非结合突变体，ATP和鸟苷5′-三磷酸（GTP）具有相同的比色响应，腺苷和鸟苷也是如此，无论DNA序列如何，表明颜色变化主要反映了核苷和核苷酸的吸附，而不是适配体结合。将使用该适体的相关文献实例分为三种类型并分别进行分析，其中报道的颜色变化都可以通过目标分析物的吸附来解释。
The 27 mer DNA aptamer for adenosine and adenosine 5′-triphosphate (ATP) is a popular model system for designing biosensors. Various strategies have been reported for label-free colorimetric detection using gold nanoparticles (AuNPs). It is generally accepted that free aptamers can protect AuNPs against salt-induced aggregation, whereas target-bound aptamers cannot. However, these studies only considered the aptamer binding to its target, and the adsorption of the aptamer on AuNPs, but none considered the adsorption of target molecules by AuNPs. We herein report that the adsorption of adenosine destabilized citrate-capped AuNPs with an apparentKdof just 7.7 μM adenosine, whereas that of ATP stabilized the AuNPs because of the negative charges from the triphosphate group. The adsorbed ATP inhibited the adsorption of DNA. Using the aptamer and a nonbinding mutant, ATP and guanosine 5′-triphosphate (GTP) had the same colorimetric response, and so did adenosine and guanosine, regardless of the DNA sequence, indicating that the color change mainly reflected the adsorption of the nucleosides and nucleotides instead of aptamer binding. The related literature examples using this aptamer were classified into three types and individually analyzed, where the reported color changes can all be explained by the adsorption of target analytes.