【作者】 刘红坡； 张蕾； 刘侠侠； 刘凯； 高传博；

【Author】 Hongpo Liu;Lei Zhang;Xiaxia Liu;Kai Liu;Chuanbo Gao;Frontier Institute of Science and Technology, Xi’an Jiaotong University;

【机构】 西安交通大学前沿科学技术技术研究院；

【摘要】 传统贵金属纳米材料的合成方法较难实现简便、大批量和严格可控的材料制备,成为制约该类材料应用的重要因素。针对这一问题,我们发展了一类独特的"基于配位作用的种晶生长体系",通过在贵金属纳米材料合成体系中引入适当的配体,显著降低了贵金属盐的还原电位,抑制了晶体生长过程中自成核现象的发生,从而实现了贵金属纳米晶严格可控的生长。基于这一方法,实现了形貌可控、尺寸连续可调的金、银纳米球和纳米片的一步法合成。在双金属纳米晶的合成中,抑制了置换反应的发生,实现了一系列以相对活泼的金属为核、贵金属为壳的新型纳米结构的可控制备(Fig.1a)。另外,针对这些材料在表面增强拉曼光谱(SERS)中的应用,我们设计了多种纳米间隙结构,如金纳米框架和多孔金纳米球等,显著提高了分子检测的灵敏度(Fig.1b);通过合金化等策略,制备了兼具稳定性和优异的光学活性的金银合金纳米球胶体,实现了较高的检测灵敏度和可靠性(Fig.1c)。更多还原

【Abstract】 A perfect synthesis of noble metal nanoparticles should be simple, scalable, and able to generate uniform products with widely-tunable sizes and shapes, which however has been a challenge in conventional synthesis, impeding them from many practical applications. In our effort to solve this problem, we developed a unique coordination-based seeded growth system. By introducing proper ligands, the reduction potential of noble metal salts can be significantly reduced, which suppresses self-nucleation events and thus enables strictly-controlled growth of the noble metal nanocrystals. Based on this method, we have achieved a one-pot synthesis of Au/Ag nanocrystals with continuously-tunable sizes, and a novel class of bimetallic nanocrystals with a noble metal as the shell and a less-stable metal as the core without involving galvanic replacement. For surface-enhanced Raman scattering(SERS) applications, nanostructures have been designed such as noble metal nanogap structures(e.g., Au nanoframes and porous nanospheres) for improved sensitivity of the analysis, and Au-Ag alloy nanospheres for combined sensitivity and reliability.更多还原