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利用配体交换反应将巯基修饰的“8-17”脱氧核酶(“8-17”DNAzyme/“8-17”Dz)底物链(17S)通过Au-S共价键自组装在纳米金胶(AuNPs)表面,制得一种新型纳米复合物17S-AuNPs。利用紫外-可见吸收光谱和动态光散射(dynamic light scattering,DLS)对其进行了表征。紫外-可见吸收光谱表明17S-AuNPs在523 nm波长处有表面等离子共振峰,较AuNPs红移了3 nm;经DLS测定的17S-AuNPs的流体动力学平均直径为38.6 nm,较AuNPs的21.8 nm增大了16.8 nm。另外,利用紫外-可见光谱和目视比色法对AuNPs和17S-AuNPs的耐盐稳定性分别进行了比较研究,结果表明:随着水溶液中Na+浓度的逐渐提高,AuNPs在600 nm处的吸收峰不断增强,溶液颜色逐渐由红变成蓝紫色;而17S-AuNPs在600 nm处并未出现吸收峰,且溶液颜色一直保持为红色;表明17S-AuNPs纳米复合物的稳定性较AuNPs显著提高。
Sulfhydryl-modified “8-17” DNAzyme (“8-17” DNAzyme / “8-17” Dz) substrate strand (17S) was covalently linked via Au- Bond self-assembled on the surface of gold nanoparticles (AuNPs), a novel nano-composite 17S-AuNPs. It was characterized by UV-Vis absorption spectroscopy and dynamic light scattering (DLS). The UV-visible absorption spectra of 17S-AuNPs showed that there was a surface plasmon resonance peak at 523 nm, which was red-shifted by 3 nm compared with AuNPs. The hydrodynamic average diameter of 17S-AuNPs measured by DLS was 38.6 nm, which was 21.8 nm Increased by 16.8 nm. In addition, the salt stability of AuNPs and 17S-AuNPs were compared by UV-Vis spectroscopy and visual colorimetric method respectively. The results showed that with the increasing of Na + concentration in aqueous solution, the absorption of AuNPs at 600 nm And the color of the solution gradually changed from red to blue-purple. However, the absorption peak of 17S-AuNPs did not appear at 600 nm and the color of the solution remained red. It showed that the stability of 17S-AuNPs nanocomposites was significantly higher than that of AuNPs .