Wu Min-Hsien, Cai Haoyuan, Xu Xia, Urban Jill P G, Cui Zhan-Feng, Cui Zheng
Department of Engineering Science, University of Oxford, UK.
Biomed Microdevices. 2005 Dec;7(4):323-9. doi: 10.1007/s10544-005-6074-y.
A microfluidic device with integrated optical fibres was developed for online monitoring of lactate. The device consists of a SU-8 waveguide, microfluidic channels and grooves for the insertion of optic fibres. It was fabricated by one-step photolithography of SU-8 polymer resist. Different channel widths (50-300 microm) were tested in terms of detection sensitivity. A wide range of flow rates were applied to investigate the influence of flow rate on signal fluctuations. The separation between optical fibre sensor and microfluidic channel and the width of fluidic channel have been optimized to maximize the detection sensitivity. It was revealed that 250 microm of channel width is the optimum light path length for a compromise between detection sensitivity and interference of ambient light. The independence of detection signals on flow rates was demonstrated within the range of flow rate (0.5-5 ml/hr) tested. Compared with conventional lactate detection, the device is proved to have high accuracy, relatively low limit of detection (50 mg/L) and reasonably fast response time (100 sec). The fabrication of device is simple and low cost. The present work has provided some fundamental data for further system optimization to meet specific detection requirements.
一种集成光纤的微流控装置被开发用于在线监测乳酸。该装置由一个SU-8波导、微流控通道和用于插入光纤的凹槽组成。它是通过对SU-8聚合物抗蚀剂进行一步光刻制造的。对不同的通道宽度（50 - 300微米）进行了检测灵敏度方面的测试。施加了广泛的流速范围以研究流速对信号波动的影响。对光纤传感器与微流控通道之间的间距以及流体通道的宽度进行了优化，以最大化检测灵敏度。结果表明，250微米的通道宽度是在检测灵敏度与环境光干扰之间取得折衷的最佳光路长度。在所测试的流速范围（0.5 - 5毫升/小时）内证明了检测信号与流速无关。与传统的乳酸检测相比，该装置被证明具有高精度、相对较低的检测限（50毫克/升）和合理快速的响应时间（100秒）。该装置的制造简单且成本低。目前的工作为进一步优化系统以满足特定检测要求提供了一些基础数据。
