School of Biological and Medical Engineering , Hefei University of Technology , Hefei , Anhui 230009 , China.
Center of Intervention Radiology, Center of Precise Medicine , Zhuhai People's Hospital , No. 79 Kangning Road , Zhuhai , Guangdong Province 519000 , China.
Langmuir. 2018 Jun 5;34(22):6628-6635. doi: 10.1021/acs.langmuir.8b01138. Epub 2018 May 21.
A hallmark of nanoscience is size-dependent and distance-dependent physical properties. Although most previous studies focused on optical properties, which are often tuned at nanometer scale, we herein report on the interaction between halide-capped gold nanoparticles (AuNPs) and phosphocholine (PC) liposomes at the sub-Angstrom level. Halide-capped AuNPs are adsorbed by PC liposomes attributable to van der Waals force. Iodide-capped AuNPs interact much more weakly with the liposomes compared with bromide- and chloride-capped AuNPs, as indicated by a liposome leakage assay and differential scanning calorimetry. This is explained by the slightly larger size of iodide separating the AuNP core more from the liposome surface. Cryo-transmission electron microscopy indicates that the liposomes remain intact when mixed with these halide-capped AuNPs of 13 or 70 nm in diameter. Other even larger ligands, including small thiol compounds, DNA oligonucleotides, proteins, and polymers, fully blocked the interaction, whereas AuNPs dispersed in noninteracting ions, including fluoride, phosphate, perchlorate, nitrate, sulfate, and bicarbonate, are still adsorbed strongly by 1,2-dioleoyl- sn-glycero-3-phosphocholine liposomes. Taken together, halides can be used to control interparticle distances at an extremely small scale with remarkable effects on materials properties, allowing surface probing, biosensor development, and fundamental surface science studies.
纳米科学的一个特点是尺寸依赖性和距离依赖性的物理性质。尽管大多数先前的研究都集中在光学性质上，这些性质通常在纳米尺度上进行调整，但我们在此报告卤化物封端的金纳米粒子（AuNPs）与磷酰胆碱（PC）脂质体之间在亚埃级别的相互作用。卤化物封端的 AuNPs 由于范德华力而被 PC 脂质体吸附。与溴化物和氯化物封端的 AuNPs 相比，碘化物封端的 AuNPs 与脂质体的相互作用弱得多，这可以通过脂质体渗漏测定和差示扫描量热法来证明。这是由于碘化物稍微增大了尺寸，从而使 AuNP 核与脂质体表面之间的距离更远。低温传输电子显微镜表明，当与直径为 13 或 70nm 的这些卤化物封端的 AuNPs 混合时，脂质体保持完整。其他更大的配体，包括小的硫醇化合物、DNA 寡核苷酸、蛋白质和聚合物，完全阻止了相互作用，而分散在非相互作用的离子（包括氟化物、磷酸盐、高氯酸盐、硝酸盐、硫酸盐和碳酸氢盐）中的 AuNPs 仍被 1,2-二油酰基-sn-甘油-3-磷酰胆碱脂质体强烈吸附。总之，卤化物可用于在极其微小的尺度上控制颗粒间的距离，对材料性能产生显著影响，从而能够进行表面探测、生物传感器开发和基础表面科学研究。
