Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan.
Talanta. 2010 Apr 15;81(1-2):493-8. doi: 10.1016/j.talanta.2009.12.030. Epub 2009 Dec 24.
In this study, we have developed a simple, cost-effective, label-free fluorescence analytical assay - comprising an adenosine-binding aptamer (Apt(Ado)), platelet-derived growth factor (PDGF)-binding aptamer (Apt(PDGF)), gold nanoparticles (Au NPs), and the DNA-binding dye Oligreen (OG) - for the determination of adenosine. Apt(Ado) and Apt(PDGF) are for the recognition of adenosine and for the amplification of fluorescence signal, respectively. The presence of adenosine induces the conformational switch of the Apt(Ado) from coiled to a G-quadruplex structure, leading to the less binding of Apt(Ado) onto the surface of Au NPs. The more the adenosine is present, the less the amount of Apt(Ado) is adsorbed, resulting in the fluorescence change of the aptamer-OG complexes. When using a mixture of Apt(Ado) (15.0 nM), Au NPs (0.1 nM), and OG (0.05 x) in 5.0mM phosphate (pH 7.4), this sensor provides the limit of detection of 70.0 nM for adenosine at a signal-to-noise ratio of 3. The LOD for adenosine is down to 5.5 nM when using Apt(Ado) modified Au NPs (Apt(Ado)-Au NPs) and Apt(PDGF) for the enrichment of adenosine and amplification of fluorescence signal of OG, respectively. The practicality of the present sensor has been validated by the determination of adenosine in diluted urine samples, showing its advantages of simplicity, selectivity, sensitivity, and minimal matrix interference.
在这项研究中，我们开发了一种简单、经济高效、无需标记的荧光分析测定法——由腺苷结合适体（Apt（Ado））、血小板衍生生长因子结合适体（Apt（PDGF））、金纳米粒子（Au NPs）和 DNA 结合染料 Oligreen（OG）组成——用于测定腺苷。Apt（Ado）和 Apt（PDGF）分别用于识别腺苷和放大荧光信号。存在腺苷会诱导 Apt（Ado）从卷曲构象到 G-四链体结构的构象转换，导致 Apt（Ado）与 Au NPs 表面的结合减少。存在的腺苷越多，吸附的 Apt（Ado）越少，导致适体-OG 复合物的荧光变化。当使用混合 Apt（Ado）（15.0 nM）、Au NPs（0.1 nM）和 OG（0.05x）在 5.0mM 磷酸盐（pH 7.4）中时，该传感器在信噪比为 3 时对腺苷的检测限为 70.0 nM。当使用 Apt（Ado）修饰的 Au NPs（Apt（Ado）-Au NPs）和 Apt（PDGF）分别用于富集腺苷和放大 OG 的荧光信号时，该传感器对腺苷的检测限可低至 5.5 nM。通过测定稀释尿液样品中的腺苷，验证了本传感器的实用性，显示了其简单、选择性、灵敏度和最小基质干扰的优点。
