温度对伸长鱼腥蓝细菌光系统 I 金属增强荧光的影响。

Temperature dependence of metal-enhanced fluorescence of photosystem I from Thermosynechococcus elongatus.

机构信息

IPTC and LISA+ Center, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.

Department of Chemical Physics and Optics, Charles University, Ke Karlovu 3, 12116 Prague, Czech Republic.

出版信息

Nanoscale. 2017 Mar 23;9(12):4196-4204. doi: 10.1039/c6nr08762k.

DOI:10.1039/c6nr08762k

PMID:28287218

Abstract

We report the temperature dependence of metal-enhanced fluorescence (MEF) of individual photosystem I (PSI) complexes from Thermosynechococcus elongatus (T. elongatus) coupled to gold nanoparticles (AuNPs). A strong temperature dependence of shape and intensity of the emission spectra is observed when PSI is coupled to AuNPs. For each temperature, the enhancement factor (EF) is calculated by comparing the intensity of individual AuNP-coupled PSI to the mean intensity of 'uncoupled' PSI. At cryogenic temperature (1.6 K) the average EF was 4.3-fold. Upon increasing the temperature to 250 K the EF increases to 84-fold. Single complexes show even higher EFs up to 441.0-fold. At increasing temperatures the different spectral pools of PSI from T. elongatus become distinguishable. These pools are affected differently by the plasmonic interactions and show different enhancements. The remarkable increase of the EFs is explained by a rate model including the temperature dependence of the fluorescence yield of PSI and the spectral overlap between absorption and emission spectra of AuNPs and PSI, respectively.

摘要

我们报告了与金纳米粒子（AuNPs）耦合的单个光系统 I（PSI）复合物的金属增强荧光（MEF）的温度依赖性来自 Thermosynechococcus elongatus（T. elongatus）。当 PSI 与 AuNPs 耦合时，发射光谱的形状和强度表现出强烈的温度依赖性。对于每个温度，通过将单个 AuNP 耦合的 PSI 的强度与“未耦合”PSI 的平均强度进行比较来计算增强因子（EF）。在低温（1.6 K）下，平均 EF 为 4.3 倍。当温度升高到 250 K 时，EF 增加到 84 倍。单个复合物的 EF 甚至高达 441.0 倍。随着温度的升高，来自 T. elongatus 的不同 PSI 光谱池变得可以区分。这些池受到等离子体相互作用的影响不同，并且表现出不同的增强。EF 的显著增加可以通过包括 PSI 的荧光产率的温度依赖性和 AuNPs 和 PSI 的吸收和发射光谱之间的光谱重叠的速率模型来解释。