Trans-Zeatin is the major active phytohormone in immature corn kernels. Herein, a highly sensitive, good selective and simple aptamer-based colorimetric method for the detection of trans-zeatin was constructed. The selected aptamer sequence binds with trans-zeatin and induces a duplex-to-aptamer structure switching. The gold nanoparticles (AuNPs) solution is stable with high-concentration salt, which is protected by red complementary DNA. In the absence of trans-zeatin, the color of AuNPs changed from red to blue because aptamer DNA and complementary DNA form double-stranded DNA. Thus, the ratio of absorbance intensities (A522/A650) of AuNPs is changed with the concentration of trans-zeatin. The color change could be observed by the naked eye. The linear range of this method covers a large variation of trans-zeatin concentration from 0.05 to 0.75 μM. The detection limit is 0.037 μM. Moreover, this method was applied successfully to detect trans-zeatin in real plant samples.

中文翻译：

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基于适体的比色探针，用于使用未修饰的金纳米粒子进行反玉米蛋白的检测

反玉米蛋白是未成熟玉米粒中的主要活性植物激素。在此，构建了一种高灵敏，选择性好，简单的基于适体的比色法检测反式玉米素。所选的适体序列与反式玉米素结合并诱导双链体至适体结构的转换。金纳米颗粒（AuNPs）溶液对高浓度盐稳定，并受红色互补DNA的保护。在不存在反式玉米素的情况下，AuNPs的颜色从红色变为蓝色，因为适体DNA和互补DNA形成双链DNA。因此，AuNPs的吸收强度之比（A522 / A650）随反式浓度而变化-玉米蛋白。可以用肉眼观察到颜色变化。该方法的线性范围占地面积大的变化反-zeatin浓度为0.05〜0.75  μ M的检测限为0.037  μ M.此外，该方法被成功地应用于检测反真实植物样品中-zeatin。