Wang Guoqing, Mitomo Hideyuki, Matsuo Yasutaka, Niikura Kenichi, Maeda Mizuo, Ijiro Kuniharu
Research Institute for Electronic Science, Hokkaido University, Kita21, Nishi10, Kita-Ku, Sapporo 001-0021, Japan; Bioengineering Laboratory, RIKEN, 2-1 Hirosawa Wako, Saitama 351-0198, Japan.
Research Institute for Electronic Science, Hokkaido University, Kita21, Nishi10, Kita-Ku, Sapporo 001-0021, Japan; JST-CREST, Sanban-Cho 5, Chiyoda-Ku, Japan.
J Colloid Interface Sci. 2015 Aug 15;452:224-234. doi: 10.1016/j.jcis.2015.04.033. Epub 2015 Apr 22.
Solution-phase synthesis and post-synthetic bio-modification have continued to play a dominant role in preparation of nanostructured biomaterials. Heterogeneous nucleation and growth that occur much more often in nature, however, remain rarely explored in nano-biomaterials research. We have newly developed a DNA-modulated photoconversion approach to uniform silver nanoparticles that afford DNA-directed recognition and multi-mode imaging. The present study was aimed at understanding the rapid heterogeneous nucleation and growth of AgNPs at the solid-liquid interface with the aid of DNA. Dynamic changes in absorbance, size and morphology of silver nanostructures were monitored and analyzed to clarify the growth kinetics, which indicated a synthetic route involving synchronous growth of silver nanostructures and the fragmentation and consumption of AgCl. Various stabilizers, including polymer and amino acids, were assessed and compared with respect to the efficacy in photoconversion of AgCl. DNA was found to offer the best monodispersity and the smallest diameter for the resultant AgNPs, due to its strong interactions to silver species as well as excellent charge dispersion ability. By controlling the physicochemical property of DNA through choice of pH and ionic strength, we have demonstrated tunable structure and composition of the nanoparticles.
溶液相合成和合成后生物修饰在纳米结构生物材料的制备中继续发挥主导作用。然而，在纳米生物材料研究中，自然界中更常发生的异质成核和生长仍然很少被探索。我们新开发了一种DNA调制的光转换方法来制备均匀的银纳米颗粒，该方法可实现DNA定向识别和多模式成像。本研究旨在借助DNA了解银纳米颗粒在固液界面的快速异质成核和生长。监测和分析了银纳米结构的吸光度、尺寸和形态的动态变化，以阐明生长动力学，这表明了一条涉及银纳米结构同步生长以及AgCl的碎片化和消耗的合成路线。评估并比较了包括聚合物和氨基酸在内的各种稳定剂对AgCl光转换的效果。由于DNA与银物种的强相互作用以及出色的电荷分散能力，发现DNA为所得银纳米颗粒提供了最佳的单分散性和最小的直径。通过选择pH值和离子强度来控制DNA的物理化学性质，我们展示了纳米颗粒的可调结构和组成。
