Size control of laser-fabricated surfactant-free gold nanoparticles with highly diluted electrolytes and their subsequent bioconjugation
Size control of laser-fabricated surfactant-free gold nanoparticles with highly diluted electrolytes and their subsequent bioconjugation
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DOI：
10.1039/c2cp42641b
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发表时间：
2013-01-01
影响因子：
3.3
通讯作者：
Barcikowski, Stephan
中科院分区：
文献类型：
--
作者：
Rehbock, Christoph;Merk, Vivian;Barcikowski, Stephan
激光制备的无表面活性剂金纳米颗粒的尺寸控制是一项具有挑战性的工作。在这项工作中，我们表明可以通过在合成过程中加入低盐度的离子来实现尺寸控制。此外，这种方法为从根本上研究离子与裸纳米颗粒表面的相互作用提供了机会，并有助于阐明纳米颗粒的形成机制。研究是在流动反应器中进行的，在最小离子强度下存在NaCl， NaBr和磷酸钠缓冲液。在1-50 μ M的离子强度下，发现了显著的尺寸淬火效应，这使得不含表面活性剂的纳米颗粒尺寸可以控制在6-30 nm的平均直径范围内。通过紫外可见光谱、透射电镜、扫描电镜和离心分析盘证实了这种效应的存在。我们的研究结果表明，尺寸猝灭源于依赖于纳米颗粒表面积的阴离子静电稳定，这可能是由特定离子吸附引起的。随后以牛血清白蛋白为稳定剂，在液体流动中进行延迟生物偶联，获得了在细胞培养基中具有良好稳定性的纳米生物偶联物，可用于毒理学和细胞生物学研究。
Size control of laser-fabricated surfactant-free gold nanoparticles is a challenging endeavor. In this work, we show that size control can be achieved by adding ions with low salinity during synthesis. In addition, this approach offers the opportunity to fundamentally study ion interactions with bare nanoparticle surfaces and can help to elucidate the nanoparticle formation mechanism. The studies were carried out in a flow-through reactor and in the presence of NaCl, NaBr and sodium phosphate buffer at minimal ionic strengths. A significant size quenching effect at ionic strengths from 1-50 mu M was found, which allowed surfactant-free nanoparticle size control with average diameters of 6-30 nm. This effect went along with low polydispersity and minimal aggregation tendencies and was confirmed by UV-vis spectroscopy, TEM, SEM and analytical disk centrifugation. Our findings indicate that size quenching originates from an anionic electrostatic stabilization depending on the nanoparticle surface area, which may be caused by specific ion adsorption. By subsequent delayed bioconjugation in liquid-flow using bovine serum albumin as a stabilizing agent, nano-bioconjugates with good stability in cell culture media were obtained, which are applicable in toxicology and cell biology.