Human telomere DNA plays a vital role in genome integrity control and carcinogenesis as an indication for extensive cell proliferation. Herein, silver nanoclusters (Ag NCs) templated by polymer and unmodified gold nanoparticles (Au NPs) are designed as a new colorimetric platform for sensitively differentiating telomere DNA with different lengths, monitoring G-quadruplex and dsDNA. Ag NCs can produce the aggregation of Au NPs, so the color of Au NPs changes to blue and the absorption peak moves to 700 nm. While the telomere DNA can protect Au NPs from aggregation, the color turns to red again and the absorption band blue shift. Benefiting from the obvious color change, we can differentiate the length of telomere DNA by naked eyes. As the length of telomere DNA is longer, the variation of color becomes more noticeable. The detection limits of telomere DNA containing 10, 22, 40, 64 bases are estimated to be 1.41, 1.21, 0.23 and 0.22 nM, respectively. On the other hand, when telomere DNA forms G-quadruplex in the presence of K⁺, or dsDNA with complementary sequence, both G-quadruplex and dsDNA can protect Au NPs better than the unfolded telomere DNA. Hence, a new colorimetric platform for monitoring structure conversion of DNA is established by Ag NCs-Au NPs system, and to prove this type of application, a selective K⁺ sensor is developed.

人类端粒DNA在基因组完整性控制和致癌作用中起着至关重要的作用，可作为广泛细胞增殖的指标。在这里，由聚合物和未修饰的金纳米颗粒（Au NPs）模板化的银纳米簇（Ag NCs）被设计为一种新的比色平台，用于敏感区分具有不同长度的端粒DNA，监测G-四链体和dsDNA。Ag NCs可以产生Au NP的聚集，因此Au NP的颜色变为蓝色，吸收峰移至700 nm。尽管端粒DNA可以保护金纳米颗粒免于聚集，但颜色再次变为红色，吸收带发生蓝移。受益于明显的颜色变化，我们可以用肉眼区分端粒DNA的长度。随着端粒DNA长度的增加，颜色的变化会变得更加明显。包含10、22、40、64个碱基的端粒DNA的检出限估计分别为1.41、1.21、0.23和0.22 nM。另一方面，当存在K时端粒DNA形成G-四链体⁺或具有互补序列的dsDNA，G-四链体和dsDNA均可比未折叠的端粒DNA更好地保护Au NP。因此，通过Ag NCs-Au NPs系统建立了一个新的比色平台，用于监测DNA的结构转化，并且为了证明这种类型的应用，开发了一种选择性的K ⁺传感器。