The neurotransmitter phenylethylamine (PEA) is highly susceptible to oxidation to produce phenylacetic acid (PA). The fact that PEA and PA are both metabolites of phenylalanine (Phe) in humans makes them important indicators in the diagnosis of phenylketonuria. In this work, three-color whole-cell biosensors were developed to simultaneously detect these analytes (Phe, PEA, and PA). The tyrosine-responsive promoter was used to control the production of green fluorescent protein signals in response to Phe levels. The FeaR regulon was first used to indicate the presence of PEA, whereas the Paa regulon was used for the detection of PA. The combination of three sensor strains together made it possible to semiquantify the three analytes according to unique color outputs without cross-interference. We sought to optimize various modular components (ribosomal binding sites and fluorescent proteins) to ensure the rapid generation of fluorescent signals. Finally, the biosensors were implemented within a microchannel device to reduce sample consumption in point-of-care assays.

中文翻译：

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使用三色全细胞生物传感器在微通道设备中同时测定l-苯丙氨酸，苯乙胺和苯乙酸

神经递质苯乙胺（PEA）极易被氧化生成苯乙酸（PA）。PEA和PA都是人体内苯丙氨酸（Phe）的代谢产物，这一事实使它们成为诊断苯丙酮尿症的重要指标。在这项工作中，开发了三色全细胞生物传感器以同时检测这些分析物（Phe，PEA和PA）。酪氨酸反应性启动子用于控制响应Phe水平的绿色荧光蛋白信号的产生。首先使用FeaR调节剂来指示PEA的存在，而使用Paa调节剂来检测PA。三种传感器应变的组合使得可以根据独特的颜色输出对三种分析物进行半定量，而不会产生交叉干扰。我们试图优化各种模块化组件（核糖体结合位点和荧光蛋白），以确保快速生成荧光信号。最后，将生物传感器安装在微通道设备中，以减少即时检验中的样品消耗。