Department of Chemical Engineering, University of Maryland, College Park, Maryland 20742, USA.
Biotechnol Bioeng. 1991 Dec 20;38(11):1292-301. doi: 10.1002/bit.260381106.
A biosensor model was developed for a commercial NADH fluorescence probe to describe the single-frequency excitation and emission fluorescence behavior of an aqueous mixture of fluorophores. This model is essential in correlating the measured signals to the concentrations of fluorescent compounds in a bioreactor. In addition to the concentrations of fluorescent components, the relevant parameters of the model are the absorbance at both the excitation and the emission frequencies by the solvent and other absorbing species, the background signals, the light path length of the bioreactor vessel, the fluorescence yield, and the lampdetector configuration. Due to inner-filter effects and other interferences, the probe signal is intrinsically nonlinear in both the fluorophore concentration and the path length. An important parameter in the model is the geometric constant, S, which accounts for variations in the monitoring efficiency throughout the sample because fluorescent light is emitted in all directions. Previous models, derived from an unrealistic assumption that fluorescent light is emitted only in one direction parallel to the probe axis, are shown to be seriously deficient. The validity of the model was verified experimentally for a single-component solution in which both the fluorophore concentration and path length were varied.
建立了一个生物传感器模型，用于描述商业 NADH 荧光探针的单频激发和发射荧光行为，该模型对于将测量信号与生物反应器中荧光化合物的浓度相关联是必不可少的。除了荧光成分的浓度外，模型的相关参数还包括溶剂和其他吸收物质在激发和发射频率处的吸光度、背景信号、生物反应器容器的光路长度、荧光产率以及灯-探测器配置。由于内滤效应和其他干扰，探针信号在荧光团浓度和光路长度上本质上是非线性的。模型中的一个重要参数是几何常数 S，它反映了由于荧光光在各个方向发射，监测效率在整个样品中变化的情况。以前的模型基于荧光光仅沿探针轴的一个方向发射的不切实际的假设，被证明存在严重的缺陷。该模型的有效性已通过单一组分溶液的实验验证，其中荧光团浓度和光路长度均发生了变化。
