Characterization of molecularly imprinted polymers with the Langmuir-Freundlich isotherm
Characterization of molecularly imprinted polymers with the Langmuir-Freundlich isotherm
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DOI：
10.1021/ac0105686
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发表时间：
2001-10-01
影响因子：
7.4
通讯作者：
Shimizu, KD
中科院分区：
文献类型：
--
作者：
Umpleby, RJ;Baxter, SC;Shimizu, KD
大多数应用于分子印迹聚合物（MIP）的结合模型都是均质模型。另一方面，MIP 是异质材料，含有具有多种结合亲和力和选择性的结合位点。证明 MIP 的结合行为可以通过异质 Langmuir-Freundlich (LF) 等温线精确建模。使用文献中的五个代表性 MIP（包括同质和异质 MIP）证明了 LF 等温线对 MIP 的适用性。以前，此类比较需要使用几种不同的结合模型和分析，包括 Langmuir 模型、Freundlich 模型和数值近似技术。相比之下，IF 模型能够直接比较具有非常不同的基础分布并在不同条件下测量的 MIP 的结合特征。可以使用 LF 拟合系数直接计算结合参数，该系数可以测量结合位点总数、平均结合亲和力和异质性。或者，LF 模型的 Langmuir 吸附积分的解使得能够根据简单代数表达式的 IN 拟合系数直接计算相应的亲和力谱，从而产生相对于缔合常数的结合位点数量的测量。最后，LF 等温线对 MIP 进行建模的能力表明，单峰异质分布是同质和异质 MIP 中分布的精确近似。
The majority of binding models that have been applied to molecularly imprinted polymers (MIPs) have been homogeneous models. MIPs' on the other hand, are heterogeneous materials containing binding sites with a wide array of binding affinities and selectivities. Demonstrated is that the binding behavior of MIPs can be accurately modeled by the heterogeneous Langmuir-Freundlich (LF) isotherm. The applicability of the LF isotherm to MIPs was demonstrated using five representative MIPs from the literature, including both homogeneous and heterogeneous MIPS. Previously, such comparisons required the use of several different binding models and analyses, including the Langmuir model, the Freundlich model, and numerical approximation techniques. In contrast, the IF model enabled direct comparisons of the binding characteristics of MIPs that have very different underlying distributions and were measured under different conditions. The binding parameters can be calculated directly using the LF fitting coefficients that yield a measure of the total number of binding sites, mean binding affinity, and heterogeneity. Alternatively, solution of the Langmuir adsorption integral for the LF model enabled direct calculation of the corresponding affinity spectrum from the IN fitting coefficients from a simple algebraic expression, yielding a measure of the number of binding sites with respect to association constant. Finally, the ability of the LF isotherm to model MIPs suggests that a unimodal heterogeneous distribution is an accurate approximation of the distribution found in homogeneous and heterogeneous MIPs.