State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, People's Republic of China.
Nanotechnology. 2011 Sep 2;22(35):355603. doi: 10.1088/0957-4484/22/35/355603. Epub 2011 Aug 9.
In this paper, a pH-inductive protein-scaffold biosynthesis of shape-tunable crystalline gold nanoparticles at room temperature has been developed. By simple manipulation of the reaction solution's pH, anisotropic gold nanoparticles including spheres, triangles and cubes could be produced by incubating an aqueous solution of sodium tetrachloroaurate with Dolichomitriopsis diversiformis biomasses after immersion in ultrapure Millipore water overnight. A moss protein with molecular weight of about 71 kDa and pI of 4.9 was the primary biomolecule involved in the biosynthesis of gold nanoparticles. The secondary configuration of the proteins by CD spectrum implied that the moss protein could display different secondary configurations including random coil, α-helix and intermediate conformations between random coil and α-helix for the experimental pH solution. The growth process of gold nanoparticles further showed that the moss protein with different configurations provided the template scaffold for the shape-controlled biosynthesis of gold nanoparticles. The constrained shape of the gold nanoparticles, however, disappeared in boiled moss extract. The gold nanoparticles with designed morphology were successfully reconstructed using the moss protein purified from the gold nanoparticles. Structural characterizations by SEM, TEM and SAED showed that the triangular and cubic gold nanoparticles were single crystalline.
本文开发了一种在室温下通过 pH 诱导的蛋白质支架生物合成可调节形状的结晶金纳米粒子的方法。通过简单地调节反应溶液的 pH 值，将金纳米粒子在经过一夜的超纯水浸泡后，用 Dolichomitriopsis diversiformis 生物量与四氯金酸钠的水溶液孵育，可以制备出各向异性的金纳米粒子，包括球体、三角形和立方体。参与金纳米粒子生物合成的主要生物分子是一种分子量约为 71 kDa、等电点为 4.9 的苔藓蛋白。圆二色谱的二级结构表明，该苔藓蛋白在实验 pH 溶液中可能呈现不同的二级结构，包括无规卷曲、α-螺旋和无规卷曲与α-螺旋之间的中间构象。金纳米粒子的生长过程进一步表明，具有不同构象的苔藓蛋白为金纳米粒子的形状控制生物合成提供了模板支架。然而，在煮沸的苔藓提取物中，金纳米粒子的约束形状消失了。使用从金纳米粒子中纯化的苔藓蛋白成功地重建了具有设计形态的金纳米粒子。SEM、TEM 和 SAED 的结构表征表明，三角形和立方体形的金纳米粒子为单晶。
