Yucknovsky Anna, Mondal Somen, Burnstine-Townley Alex, Foqara Mohammad, Amdursky Nadav
Schulich Faculty of Chemistry , Technion - Israel Institute of Technology , Haifa 3200003 , Israel.
Nano Lett. 2019 Jun 12;19(6):3804-3810. doi: 10.1021/acs.nanolett.9b00952. Epub 2019 May 24.
Dynamic self-assembly of nanoparticles (NPs) for the formation of aggregates takes place out of thermodynamic equilibrium and is sustained by external energy supply. Herein, we present light energy driven dynamic self-assembly process of AuNPs, decorated with pH sensitive ligands. The process is being controlled by the use of photoacids and photobases that undergo excited state proton or hydroxide transfer, respectively, due to their large p K change between their ground and excited electronic states. The unique design is underlined by record subsecond conversion rates between the assembled and disassembled AuNPs states, and the ability to control the process using only light of different wavelengths. Measurements in both aqueous and nonaqueous solutions resulted in different self-assembly mechanisms, hence showing the wide versatility of photoacids and photobases for dynamic processes.
纳米粒子（NPs）动态自组装形成聚集体的过程是在热力学平衡之外发生的，并由外部能量供应维持。在此，我们展示了用pH敏感配体修饰的金纳米粒子（AuNPs）的光能驱动动态自组装过程。该过程通过使用光酸和光碱来控制，由于它们在基态和激发态电子态之间存在较大的pK变化，分别经历激发态质子或氢氧根转移。组装态和解离态AuNPs之间创纪录的亚秒级转换率以及仅使用不同波长的光来控制该过程的能力突出了这种独特设计。在水溶液和非水溶液中的测量产生了不同的自组装机制，从而展示了光酸和光碱在动态过程中的广泛通用性。
