Fluorescing aptamer-gold nanosensors for enhanced sensitivity to bisphenol A
Fluorescing aptamer-gold nanosensors for enhanced sensitivity to bisphenol A
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DOI：
10.1016/j.snb.2018.01.018
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发表时间：
2018-05-01
影响因子：
8.4
通讯作者：
Kim, Young-Pil
中科院分区：
文献类型：
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作者：
Lee, Eun-Song;Kim, Gae Baik;Kim, Young-Pil
适体结合比色金纳米粒子（AuNPs）的灵敏度不足是环境化学品检测中的常见挑战。我们报告了使用一种改进的适配体/金纳米粒子为基础的传感器结合荧光单链DNA适配体的双酚A（BPA），这是一种主要的内分泌干扰物（EDC）的灵敏检测。当抗BPA单链DNA适体与BPA结合时，在添加SYBR Green-I（SG-I）后观察到弱荧光信号，所述SYBR Green-I（SG-I）对游离适体的双链体区域具有特异性。该反应伴随着未修饰的AuNP（柠檬酸盐稳定的AuNP）在高盐浓度下的亚微米聚集，导致颜色从微红变为紫色。相比之下，BPA的不存在引起了来自SG-1的高荧光信号，并且即使在添加盐离子后，在AuNP溶液中也不产生颜色变化。与在其末端用荧光团标记的适体不同，我们的策略既没有引起靶结合亲和力的损失，也没有引起AuNP比色法的扰动。因此，在BPA浓度超过四个数量级时，通过结合荧光和比色测量，实现了具有宽动态范围的定量分析。我们的方法还产生了比经典AuNP比色法或其他适体组合方法更高的检测灵敏度（低至9 pg.mL（1））。此外，该方法能够在从热敏纸中提取的小部分中检测BPA，在EDCs中具有高特异性。我们预计，这种方法将促进在传统的金纳米粒子比色传感器的设计，使用不同的适配体在环境和临床领域的化学传感的进一步进展。(c)2018 Elsevier B. V.版权所有。
An insufficient sensitivity of aptamer-integrated colorimetric gold nanoparticles (AuNPs) is a common challenge in the detection of environmental chemicals. We report the use of a modified aptamer/AuNP-based sensor in conjunction with a fluorescing single-stranded DNA aptamer for the sensitive detection of bisphenol A (BPA), which is a major endocrine disruptor (EDC). While an anti-BPA single-stranded DNA aptamer was bound with BPA, a weak fluorescence signal was observed upon the addition of SYBR Green-I (SG-I), which is specific to a duplex region of the free aptamer. This reaction was accompanied by a sub-sequent aggregation of unmodified AuNPs (citrate-stabilized AuNPs) at high salt concentrations, leading to a color change from reddish to purple. In contrast, the absence of BPA elicited a high fluorescence signal from SG-I and produced no color change in the AuNP solution even upon the addition of salt ions. Unlike aptamers that are labeled at their ends with fluorophores, our strategy gave rise to neither a loss of target-binding affinity nor a perturbation of the AuNP colorimetry. Thus, a quantitative analysis witha broad dynamic range was achieved by combining the fluorescent and colorimetric measurements at BPA concentrations ranging over four orders of magnitude. Our approach also yielded a greater detection sensitivity (as low as 9 pg.mL(1)) than classical AuNP colorimetry or other aptamer-combined methods Moreover, this method enabled the detection of BPA in a small fraction extracted from thermal paper with a high specificity among EDCs. We anticipate that this approach will facilitate further advances in the design of traditional AuNP colorimetric sensors using different aptamers for chemical sensing in the environmental and clinical fields. (c) 2018 Elsevier B.V. All rights reserved.