Key Laboratory for Advanced Materials, School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, P. R. China.
Angew Chem Int Ed Engl. 2018 Mar 26;57(14):3758-3762. doi: 10.1002/anie.201710568. Epub 2018 Mar 9.
An ultrasensitive photoelectrochemical method for achieving real-time detection of single nanoparticle collision events is presented. Using a micrometer-thick nanoparticulate TiO -filmed Au ultra-microelectrode (TiO @Au UME), a sub-millisecond photocurrent transient was observed for an individual N719-tagged TiO (N719@TiO ) nanoparticle and is due to the instantaneous collision process. Owing to a trap-limited electron diffusion process as the rate-limiting step, a random three-dimensional diffusion model was developed to simulate electron transport dynamics in TiO film. The combination of theoretical simulation and high-resolution photocurrent measurement allow electron-transfer information of a single N719@TiO nanoparticle to be quantified at single-molecule accuracy and the electron diffusivity and the electron-collection efficiency of TiO @Au UME to be estimated. This method provides a test for studies of photoinduced electron transfer at the single-nanoparticle level.
提出了一种用于实时检测单个纳米颗粒碰撞事件的超灵敏光电化学方法。使用微米厚的纳米颗粒 TiO 涂覆的 Au 超微电极（TiO@Au UME），观察到单个 N719 标记的 TiO（N719@TiO）纳米颗粒的亚毫秒级光电流瞬变，这是由于瞬时碰撞过程。由于电子扩散过程受到陷阱限制，是限速步骤，因此开发了一个随机三维扩散模型来模拟 TiO 薄膜中的电子输运动力学。理论模拟和高分辨率光电流测量的结合允许以单分子精度量化单个 N719@TiO 纳米颗粒的电子转移信息，并估计 TiO@Au UME 的电子扩散率和电子收集效率。该方法为在单个纳米颗粒水平上研究光诱导电子转移提供了一种测试方法。
