Queiroz A M, Mezacasa A V, Graciano D E, Falco W F, M'Peko J-C, Guimarães F E G, Lawson T, Colbeck I, Oliveira S L, Caires A R L
Grupo de Óptica e Fotônica, Instituto de Física, Universidade Federal de Mato Grosso do Sul, CP 549, 79070-900 Campo Grande, MS, Brazil; Grupo de Óptica Aplicada, Universidade Federal da Grande Dourados, CP 533, 79804-970 Dourados, MS, Brazil.
Grupo de Óptica Aplicada, Universidade Federal da Grande Dourados, CP 533, 79804-970 Dourados, MS, Brazil.
Spectrochim Acta A Mol Biomol Spectrosc. 2016 Nov 5;168:73-77. doi: 10.1016/j.saa.2016.05.033. Epub 2016 May 25.
The interaction between chlorophyll (Chl) and silver nanoparticles (AgNPs) was evaluated by analyzing the optical behavior of Chl molecules surrounded by different concentrations of AgNPs (10, 60, and 100nm of diameter). UV-Vis absorption, steady state and time-resolved fluorescence measurements were performed for Chl in the presence and absence of these nanoparticles. AgNPs strongly suppressed the Chl fluorescence intensity at 678nm. The Stern-Volmer constant (KSV) showed that fluorescence suppression is driven by the dynamic quenching process. In particular, KSV was nanoparticle size-dependent with an exponential decrease as a function of the nanoparticle diameter. Finally, changes in the Chl fluorescence lifetime in the presence of nanoparticles demonstrated that the fluorescence quenching may be induced by the excited electron transfer from the Chl molecules to the metal nanoparticles.
通过分析被不同浓度（直径分别为10、60和100纳米）的银纳米颗粒（AgNPs）包围的叶绿素（Chl）分子的光学行为，评估了叶绿素与银纳米颗粒之间的相互作用。对存在和不存在这些纳米颗粒的叶绿素进行了紫外-可见吸收、稳态和时间分辨荧光测量。AgNPs强烈抑制了678纳米处的Chl荧光强度。斯特恩-沃尔默常数（KSV）表明，荧光抑制是由动态猝灭过程驱动的。特别是，KSV与纳米颗粒尺寸有关，随着纳米颗粒直径的增加呈指数下降。最后，存在纳米颗粒时Chl荧光寿命的变化表明，荧光猝灭可能是由Chl分子向金属纳米颗粒的激发电子转移引起的。
