Organic Nanoparticles: Mechanism of Electron Transfer to Indigo Nanoparticles
Organic Nanoparticles: Mechanism of Electron Transfer to Indigo Nanoparticles
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DOI：
10.1002/celc.201300233
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发表时间：
2014-04-15
期刊：
影响因子：
4
通讯作者：
Compton, Richard G.
中科院分区：
文献类型：
--
作者：
Cheng, Wei;Batchelor-McAuley, Christopher;Compton, Richard G.
有机纳米粒子在生物成像和纳米医学中有着重要的应用。然而，与金属纳米粒子和无机纳米粒子的深入研究相比，有机纳米粒子由于其复杂的物理和化学性质，其研究还处于非常早期的阶段。近年来，人们对基于有机材料的纳米电容器、纳米级储能和传感器器件的开发越来越感兴趣。本文首次以靛蓝纳米粒子为模型体系，通过对单个有机纳米粒子还原过程中电荷转移的分析，报道了电子转移到单个有机纳米粒子的动力学和机制。我们得出结论，靛蓝纳米粒子表现出不可逆（缓慢）的电子转移动力学，并且电荷转移是纳米粒子还原溶解的速率决定步骤；质子化和分子脱离纳米粒子发生在这个速率决定步骤之后。发现电子转移的传递系数a为0.25 +/- 0.05，而速率常数（k(0)）确定为复合参数k(0) exp(0.25 f /RT E-f(theta))，其中E-f（theta）是形式势，其值为1.7 x 10(-8) ms（-1）。鉴于有机纳米材料的电子转移机制的重要性，该报告可能对未来有机纳米材料的各种应用研究具有重要意义。
Organic nanoparticles are attracting many significant applications in bio-imaging and nanomedicine. However, in comparison with intensive studies of metal and inorganic nanoparticles, the research of organic nanoparticles is still at a very early stage due to their complex physical and chemical properties. Most recently, there are increasingly significant interests in developing nano-capacitors and nano-scale energy storage and sensor devices based on organic materials. Herein, we report for the first time the kinetics and mechanism of electron transfer to individual organic nanoparticles, using indigo nanoparticles as a model system, via analysis of the charge transferred in the reduction of individual organic nanoparticles. We conclude the indigo nanoparticles display irreversible (slow) electron transfer kinetics and that the charge transfer is the rate-determining step in the reductive dissolution of the nanoparticles; protonation and detachment of molecules from the nanoparticles occurs after this rate-determining step. The transfer coefficient, a, of the electron transfer is found to be 0.25 +/- 0.05, whilst the rate constant (k(0)) is determined as the composite parameter k(0) exp(0.25F/RT E-f(theta)) where E-f(theta) is the formal potential, which is found to have the value of 1.7 x 10(-8) ms(-1). Given the high importance of the electron transfer mechanism for organic nanomaterials, this report may have great significance on future research of organic nanomaterials for diverse applications.