A.N. Bach Institute of Biochemistry, Research Centre of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia.
Int J Mol Sci. 2024 Sep 20;25(18):10108. doi: 10.3390/ijms251810108.
A promising and sought-after class of nanozymes for various applications is Pt-containing nanozymes, primarily Au@Pt, due to their easy preparation and remarkable catalytic properties. This study aimed to explore the freeze-thaw method for functionalizing Pt-containing nanozymes with oligonucleotides featuring a polyadenine anchor. Spherical gold nanoparticles ([Au]NPs) were synthesized and subsequently used as seeds to produce urchin-like Au@Pt nanoparticles ([Au@Pt]NPs) with an average diameter of 29.8 nm. The nanoparticles were conjugated with a series of non-thiolated DNA oligonucleotides, each consisting of three parts: a 5'-polyadenine anchor (A, with n = 3, 5, 7, 10; triple-branched A, or triple-branched A), a random sequence of 23 nucleotides, and a linear polyT block consisting of seven deoxythymine residues. The resulting conjugates were characterized using transmission electron microscopy, spectroscopy, dynamic light scattering, and emission detection of the fluorescent label at the 3'-end of each oligonucleotide. The stability of the conjugates was found to depend on the type of oligonucleotide, with decreased stability in the row of [Au@Pt]NP conjugates with A > A > 3A > 3A > A > A anchors. These [Au@Pt]NP-oligonucleotide conjugates were further evaluated using lateral flow test strips to assess fluorescein-specific binding and peroxidase-like catalytic activity. Conjugates with A, A, A, and 3A anchors showed the highest levels of signals of bound labels on test strips, exceeding conjugates in sensitivity by up to nine times. These findings hold significant potential for broad application in bioanalytical systems.
一种有前途且备受追捧的纳米酶，适用于各种应用，是含铂纳米酶，主要是 Au@Pt，因为它们易于制备和具有显著的催化性能。本研究旨在探索冻融法，用带有聚腺嘌呤锚的寡核苷酸功能化含铂纳米酶。合成了球形金纳米粒子([Au]NPs)，并随后用作种子，以制备平均直径为 29.8nm 的刺猬状 Au@Pt 纳米粒子([Au@Pt]NPs)。这些纳米粒子与一系列非硫醇化的 DNA 寡核苷酸连接，每个寡核苷酸由三部分组成：5'-聚腺嘌呤锚(A，n=3、5、7、10；三分支 A，或三分支 A)、23 个核苷酸的随机序列和由七个脱氧胸腺嘧啶残基组成的线性聚 T 块。使用透射电子显微镜、光谱学、动态光散射和荧光标记在每个寡核苷酸 3'-末端的发射检测对所得缀合物进行了表征。缀合物的稳定性取决于寡核苷酸的类型，具有 A> A>3A>3A> A> A 锚的 [Au@Pt]NP 缀合物的稳定性降低。进一步使用侧流测试条评估了这些 [Au@Pt]NP-寡核苷酸缀合物，以评估荧光素特异性结合和过氧化物酶样催化活性。具有 A、A、A 和 3A 锚的缀合物在测试条上显示出最高的结合标记信号水平，比敏感性提高了多达九倍。这些发现为在生物分析系统中的广泛应用提供了重要的潜力。
