Schappacher Gudrun, Hartmann Paul
Roche Diagnostics GmbH, Kratkystrasse 2, A-8020 Graz, Austria.
Anal Chem. 2003 Aug 15;75(16):4319-24. doi: 10.1021/ac034098m.
Many aspects of optical chemical sensor design would benefit from a better knowledge of the diffusion properties of the analyte in the polymer host. The response times of such sensors to a step change of analyte concentration are of vital interest for many applications of fast-responding sensors. Further, the diffusion properties govern their quenching behavior and their sensitivity. A method for determination of the diffusion constant of oxygen in polymers has been developed and used by several groups in the past. The underlying mathematical model for luminescence quenching by molecules of a gas in a single sensing layer on an impermeable support has not yet been completely derived in an analytical form and still uses tedious numerical methods. We present a partial analytical solution to the problem of modeling the time dependence of luminescence generated by in- or out-diffusion of a gaseous quencher in a polymer film in which a luminophor is immobilized and offer a suitable method to predict sensor response times.
光学化学传感器设计的许多方面将受益于对分析物在聚合物基质中扩散特性的更深入了解。对于快速响应传感器的许多应用而言，此类传感器对分析物浓度阶跃变化的响应时间至关重要。此外，扩散特性决定了它们的猝灭行为及其灵敏度。过去已有几个研究小组开发并使用了一种测定聚合物中氧扩散常数的方法。关于在不可渗透载体上的单个传感层中气体分子引起发光猝灭的基础数学模型尚未完全以解析形式推导出来，仍然使用繁琐的数值方法。我们给出了一个部分解析解，用于模拟在固定有发光体的聚合物薄膜中气态猝灭剂内扩散或外扩散所产生的发光随时间的变化，并提供了一种合适的方法来预测传感器的响应时间。
