Quick and efficient immobilization of DNAs on gold nanoclusters (AuNCs) has a substantial impact on nanoscale applications relative to molecular recognition and patterned assembly. We found that in the presence of tris(2-carboxyethyl)phosphine (TCEP), chemisorption of thiolated DNA on the AuNC surface could be accomplished within 1.5 h, which was dramatically shorter than the incubation time needed in the conventional thiolate exchange reactions. Based on this observation, a core-shell-satellite nanocomposite consisting of magnetic nanoparticle, silica coating, and AuNCs (FeONPs@SiO@AuNCs) was fabricated, on which a fluorescent hairpin probe was anchored with the assistance of TCEP. Integrated with duplex-specific nuclease (DSN)-assisted target recycling strategy, the sensing platform could simultaneously detect microRNA-21 and microRNA-141 with detection limits of 0.020 and 0.017 pM, respectively. The feasibility of the developed immobilization approach might significantly advance the use of DNAs and AuNCs in analytical sciences and clinical research.

中文翻译：

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三(2-羧乙基)膦介导的硫醇化DNA在金纳米簇上的固定化及其在多重microRNA检测中的应用

DNA 快速有效地固定在金纳米簇 (AuNC) 上对分子识别和图案组装相关的纳米级应用具有重大影响。我们发现，在三（2-羧乙基）膦（TCEP）存在的情况下，硫醇化DNA在AuNC表面的化学吸附可以在1.5小时内完成，这比传统硫醇盐交换反应所需的孵育时间要短得多。基于这一观察，制备了由磁性纳米颗粒、二氧化硅涂层和AuNCs（FeONPs@SiO@AuNCs）组成的核-壳-卫星纳米复合材料，并在TCEP的帮助下将荧光发夹探针固定在其上。与双链体特异性核酸酶（DSN）辅助的目标回收策略相结合，该传感平台可以同时检测microRNA-21和microRNA-141，检测限分别为0.020和0.017 pM。所开发的固定方法的可行性可能会显着促进 DNA 和 AuNC 在分析科学和临床研究中的使用。