Nakache M, Dimicoli J L
Biophys J. 1984 Sep;46(3):357-69. doi: 10.1016/S0006-3495(84)84032-1.
A new technique of visualization of diffusion-convection phenomena at a solid-liquid interface using the luminol chemiluminescent reaction catalyzed by immobilized peroxidase has been previously described (Dimicoli, J.L., M. Nakache, and P. Peronneau, 1982, Biorheology, 19:281-300). We propose now a theoretical model that predicts quantitatively the light fluxes, JL, corresponding to the transfer J of the hydrogen peroxide substrate at the liquid-solid interface in a cylindrical tube for continuous flow experiments. A simple phenomenological relation, J alpha J1/mL (1 less than m less than 3) was first established for each point of the wall. Then, numerical integration showed that, independent of the laminar or turbulent character of the flow, J1/mL was proportional to (S1 Kideal)/(1 + Kideal/ET), where S1 is the bulk substrate concentration, Kideal is the ideal transport coefficient, and ET (in cm.S-1) a phenomenological first-order enzymatic rate constant per unit of wall surface. This relation proved to be satisfactory for all experimental conditions since a single mean value of ET takes into account the experimental data collected for a given enzymated tube in a large range of Reynolds number values (Re) (500 less than Re less than 9,000) and of distances from the entrance of the tube (chi greater than 0.3 cm). This quantitative analysis using a pseudo-first-order approximation interprets the observed great dependence of JL on Re(JL alpha Ren', with n' usually greater than 1/3 for laminar flows) and on S1 (JL alpha S1m). It predicts also that the laminar-to-turbulent transition can be evidenced for interfacial enzymatic activity, ET greater than 2.10(-4) cm.S-1, as observed with most of the tubes prepared by covalent binding of peroxidase on the acrylamide gel wall. The experiment had to be carried out at a pH value of 8, which corresponds to the fastest rate of the chemiluminescent reaction. The predicted entrance effects were also observed experimentally for the first time in an immobilized enzyme system. This technique appears therefore to be a valuable tool for the quantitative analysis of diffusion-convection phenomena at a liquid-solid interface with a good spatial resolution with a great range of flow rate.
先前已描述了一种利用固定化过氧化物酶催化的鲁米诺化学发光反应来可视化固液界面扩散-对流现象的新技术（迪米科利，J.L.，M. 纳卡什，以及 P. 佩罗诺，1982 年，《生物流变学》，19:281 - 300）。我们现在提出一个理论模型，该模型定量预测在连续流动实验中，对应于圆柱形管中液固界面过氧化氢底物转移量 J 的光通量 JL。首先为管壁的每个点建立了一个简单的唯象关系，J α J1/mL（1 < m < 3）。然后，数值积分表明，无论流动是层流还是湍流特性，J1/mL 与 (S1 Kideal)/(1 + Kideal/ET) 成正比，其中 S1 是底物的总体浓度，Kideal 是理想传输系数，ET（单位为 cm·s⁻¹）是单位壁面的唯象一级酶促速率常数。由于单一的 ET 平均值考虑了在给定酶促管中在大范围雷诺数（Re）值（500 < Re < 9000）和距管入口距离（χ > 0.3 cm）下收集的实验数据，所以该关系在所有实验条件下都被证明是令人满意的。这种使用伪一级近似的定量分析解释了观察到的 JL 对 Re（JL α Ren'，层流时 n' 通常大于 1/3）和对 S1（JL α S1m）的强烈依赖性。它还预测，对于界面酶活性 ET > 2.10⁻⁴ cm·s⁻¹，如通过过氧化物酶共价结合在丙烯酰胺凝胶壁上制备的大多数管子所观察到的那样，可以证明层流到湍流的转变。实验必须在 pH 值为 8 的条件下进行，这对应于化学发光反应的最快速率。在固定化酶系统中，预测的入口效应也首次通过实验观察到。因此，该技术似乎是一种用于定量分析液固界面扩散-对流现象的有价值工具，具有良好的空间分辨率和大范围的流速。
