Zhang Zhi-Feng, Cui Hua, Shi Ming-Juan
Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Phys Chem Chem Phys. 2006 Feb 28;8(8):1017-21. doi: 10.1039/b511917k. Epub 2005 Dec 8.
It was found that potassium permanganate (KMnO(4)) could react with gold nanoparticles in a strong acid medium to generate particle size-dependent chemiluminescence (CL). For gold nanoparticles with the size of 2.6 or 6.0 nm, the reaction was fast and could produce the excited state Mn(II) with light emission around 640 nm. For gold nanoparticles larger than 6.0 nm, no light emission was observed due to a much slower reaction rate. The CL intensity was found to increase linearly with the concentration of 2.6 nm gold nanoparticles. The effects of the acid medium, concentration of KMnO(4) and presence of N(2) and O(2) were investigated. UV-Vis absorption spectra and X-ray photoelectron spectra (XPS) measured before and after the CL reaction were analyzed. A CL mechanism has been proposed suggesting that the potassium permanganate was reduced by gold nanoparticles in the strong acid medium to the excited state Mn(II), yielding light emission. The results bestow new light on the size-dependent chemical reactivities of the gold nanoparticles and on nanoparticle-induced chemiluminescence. The CL reaction was considered to be of potential use for bioanalysis applications.
研究发现，高锰酸钾（KMnO₄）在强酸介质中能与金纳米颗粒发生反应，产生与颗粒大小相关的化学发光（CL）。对于尺寸为2.6或6.0 nm的金纳米颗粒，反应迅速，能产生激发态的Mn(II)，发射波长约为640 nm的光。对于尺寸大于6.0 nm的金纳米颗粒，由于反应速率慢得多，未观察到发光现象。发现化学发光强度与2.6 nm金纳米颗粒的浓度呈线性增加。研究了酸性介质、KMnO₄浓度以及N₂和O₂的存在对反应的影响。分析了化学发光反应前后测量的紫外可见吸收光谱和X射线光电子能谱（XPS）。提出了一种化学发光机制，表明在强酸介质中，高锰酸钾被金纳米颗粒还原为激发态的Mn(II)，从而产生发光。这些结果为金纳米颗粒的尺寸依赖性化学反应活性和纳米颗粒诱导的化学发光提供了新的认识。该化学发光反应被认为在生物分析应用中具有潜在用途。
