Institut für Analytische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany.
Lab Chip. 2013 Oct 21;13(20):4134-41. doi: 10.1039/c3lc50387a. Epub 2013 Aug 23.
Real-time chemical reaction monitoring in microfluidic environments is demonstrated using luminescent chemical sensors integrated in PDMS/glass-based microscale reactors. A fabrication procedure is presented that allows for straightforward integration of thin polymer layers with optical sensing functionality in microchannels of glass-PDMS chips of only 150 μm width and of 10 to 35 μm height. Sensor layers consisting of polystyrene and an oxygen-sensitive platinum porphyrin probe with film thicknesses of about 0.5 to 4 μm were generated by combining spin coating and abrasion techniques. Optimal coating procedures were developed and evaluated. The chip-integrated sensor layers were calibrated and investigated with respect to stability, reproducibility and response times. These microchips allowed observation of dissolved oxygen concentration in the range of 0 to over 40 mg L(-1) with a detection limit of 368 μg L(-1). The sensor layers were then used for observation of a model reaction, the oxidation of sulphite to sulphate in a microfluidic chemical reactor and could observe sulphite concentrations of less than 200 μM. Real-time on-line monitoring of this chemical reaction was realized at a fluorescence microscope setup with 405 nm LED excitation and CCD camera detection.
在 PDMS/玻璃基微尺度反应器中集成发光化学传感器，实现微流环境中的实时化学反应监测。提出了一种制造工艺，允许在仅 150 μm 宽和 10 到 35 μm 高的玻璃-PDMS 芯片的微通道中，直接集成具有光学传感功能的薄聚合物层。传感器层由聚苯乙烯和氧敏铂卟啉探针组成，膜厚约为 0.5 到 4 μm，通过旋涂和磨损技术相结合生成。开发并评估了最佳的涂层工艺。对芯片集成的传感器层进行了校准，并就稳定性、重现性和响应时间进行了研究。这些微芯片可以观察到 0 到 40 mg/L 以上范围内的溶解氧浓度，检测限为 368 μg/L。然后，将传感器层用于观察模型反应，即在微流化学反应器中亚硫酸盐氧化为硫酸盐，并可以观察到低于 200 μM 的亚硫酸盐浓度。通过配备 405nm LED 激发和 CCD 相机检测的荧光显微镜装置，实现了对该化学反应的实时在线监测。
