Boens Noël, Novikov Eugene, Van der Auweraer Mark
Department of Chemistry and Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200f - bus 02404, 3001 Heverlee, Belgium.
Math Biosci. 2007 Oct;209(2):624-43. doi: 10.1016/j.mbs.2007.04.006. Epub 2007 Apr 29.
The parameters describing the kinetics of excited-state processes can possibly be recovered by analysis of the fluorescence decay surface measured as a function of the experimental variables. The identifiability analysis of a photophysical model assuming errorless time-resolved fluorescence data can verify whether the model parameters can be determined. In this work, we have used the methods of similarity transformation and Taylor series to investigate the identifiability of two models utilized to describe the time-resolved fluorescence quenching of stationary probes in micelles. The first model assumes that exchange of the quencher between micelles is much slower than the fluorescence decay of the unquenched probe (the 'immobile' quencher model). The second model assumes that quenchers exchange between the aqueous and micellar phases (the 'mobile' quencher model). For the 'immobile' quencher model, the rate constants for deactivation (k(0)) and quenching (k(q)) of the excited probe are uniquely identified together with the average number of quencher molecules per micelle. For the 'mobile' quencher model, the rate constants k(0) and k(q) are uniquely identified, as are the rate constants for entry (k(+)) and exit (k(-)) of one quencher molecule into and from a micelle, and the micellar aggregation number. The concomitant rate equations describing the time-resolved fluorescence are solved using z-transforms.
描述激发态过程动力学的参数可能通过分析作为实验变量函数测量的荧光衰减表面来恢复。假设时间分辨荧光数据无误的光物理模型的可识别性分析可以验证模型参数是否可以确定。在这项工作中，我们使用相似变换和泰勒级数的方法来研究用于描述胶束中固定探针的时间分辨荧光猝灭的两个模型的可识别性。第一个模型假设猝灭剂在胶束之间的交换比未猝灭探针的荧光衰减慢得多（“固定”猝灭剂模型）。第二个模型假设猝灭剂在水相和胶束相之间交换（“移动”猝灭剂模型）。对于“固定”猝灭剂模型，激发探针的失活速率常数（k(0)）和猝灭速率常数（k(q)）与每个胶束中猝灭剂分子的平均数一起被唯一确定。对于“移动”猝灭剂模型，速率常数k(0)和k(q)被唯一确定，一个猝灭剂分子进入和离开胶束的进入速率常数（k(+)）和离开速率常数（k(-)）以及胶束聚集数也被唯一确定。使用z变换求解描述时间分辨荧光的伴随速率方程。
