Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1.
J Am Chem Soc. 2012 Jun 20;134(24):9910-3. doi: 10.1021/ja303787e. Epub 2012 Jun 6.
For many applications, it is desirable to stabilize colloids over a wide range of buffer conditions while still retaining surface accessibility for adsorption and reaction. Commonly used charge or steric stabilization cannot achieve this goal since the former is sensitive to salt and the latter blocks the particle surface. We use depletion stabilization in the presence of high molecular weight polyethylene glycol (PEG) to stabilize a diverse range of nanomaterials, including gold nanoparticles (from 10 to 100 nm), graphene oxide, quantum dots, silica nanoparticles, and liposomes in the presence of Mg(2+) (>1.6 M), heavy metal ions, extreme pH (pH 1-13), organic solvents, and adsorbed nucleosides and drugs. At the same time, the particle surface remains accessible for adsorption of both small molecules and macromolecules. Based on this study, high loading of thiolated DNA was achieved in one step with just 2% PEG 20,000 in 2 h.
对于许多应用来说，理想的情况是在广泛的缓冲条件下稳定胶体，同时仍保持吸附和反应的表面可及性。常用的电荷或空间稳定化方法无法实现这一目标，因为前者对盐敏感，后者则会阻碍颗粒表面。我们使用在高分子量聚乙二醇（PEG）存在下的耗尽稳定化来稳定各种纳米材料，包括金纳米粒子（10 到 100nm）、氧化石墨烯、量子点、二氧化硅纳米粒子和脂质体，在存在 Mg（2+）（>1.6M）、重金属离子、极端 pH 值（pH 1-13）、有机溶剂以及吸附的核苷和药物的情况下。同时，颗粒表面仍可用于小分子和大分子的吸附。基于这项研究，仅用 2%的 PEG20000 在 2 小时内即可一步实现巯基化 DNA 的高负载量。
