State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province , Hunan University , Changsha 410082 , China.
ACS Appl Mater Interfaces. 2019 Oct 30;11(43):40817-40825. doi: 10.1021/acsami.9b13659. Epub 2019 Oct 16.
The real application of DNA-functionalized gold nanoparticles (DNA-Au NPs) was limited by decreased stability and irreversible aggregation in high-ionic strength solutions and complex systems. Therefore, exploring a kind of DNA-Au NPs with excellent stability in high-ionic strength solutions and complex systems is challenging and significant. Herein, a novel universal bioconjugate strategy for constructing ultrastable DNA-Au NPs was designed based on the combination of polydopamine (PDA) shell and DNA linker. The obtained DNA-linked Au@polydopamine nanoparticles (DNA-Au@PDA NPs) showed colloidal stability in high-ionic strength solution and complex systems (such as human serum and cell culture supernatant). Moreover, the nanoparticles still maintained good dispersion after multiple freeze-thaw cycles. The high stability of DNA-Au@PDA NPs may be attributed to increasing the electrostatic and steric repulsions among nanoparticles through the effect of both PDA shell and DNA linker on Au@PDA NPs. For investigating the application of such nanoparticles, a highly sensitive assay for miRNA 141 detection was developed using DNA-Au@PDA NPs coupled with dynamic light scattering (DLS). Comparing with the regular DNA-Au NPs, DNA-Au@PDA NPs could detect as low as 50 pM miRNA 141 even in human whole serum. Taken together, the features of Bio/Nanointerface make the nanoparticle suitable for various applications in harsh biological and environmental conditions due to the stability. This work may provide a universal modification method for obtaining stable nanoparticles.
DNA 功能化金纳米粒子（DNA-Au NPs）的实际应用受到高离子强度溶液和复杂体系中稳定性降低和不可逆聚集的限制。因此，探索一种在高离子强度溶液和复杂体系中具有优异稳定性的 DNA-Au NPs 具有挑战性和重要意义。本文设计了一种基于聚多巴胺（PDA）壳和 DNA 连接子结合的构建超稳定 DNA-Au NPs 的新型通用生物缀合策略。所得到的 DNA 连接的 Au@聚多巴胺纳米粒子（DNA-Au@PDA NPs）在高离子强度溶液和复杂体系（如人血清和细胞培养上清液）中表现出胶体稳定性。此外，纳米粒子在多次冻融循环后仍保持良好的分散性。DNA-Au@PDA NPs 的高稳定性可能归因于 PDA 壳和 DNA 连接子对 Au@PDA NPs 的共同作用，增加了纳米粒子之间的静电和空间排斥。为了研究这些纳米粒子的应用，采用 DNA-Au@PDA NPs 与动态光散射（DLS）结合，开发了一种用于 miRNA 141 检测的高灵敏测定方法。与常规 DNA-Au NPs 相比，DNA-Au@PDA NPs 甚至在人全血清中也能检测到低至 50 pM 的 miRNA 141。总之，由于其稳定性，Bio/Nanointerface 的特点使纳米粒子适合在恶劣的生物和环境条件下的各种应用。这项工作可能为获得稳定的纳米粒子提供了一种通用的修饰方法。
