T U Vinitha, Ghosh Sthitodhi, Milleman Alexander, Nguyen Thinh, Ahn Chong H
Microsystems and BioMEMS Laboratory, Department of Electrical Engineering and Computing Systems, University of Cincinnati, Cincinnati, OH 45221, USA.
Lab Chip. 2020 Jun 2;20(11):1961-1974. doi: 10.1039/d0lc00071j.
Unbound cortisol in saliva, which can be detected with non-invasive sampling, is now considered as one of the most effective biomarkers for the biochemical evaluation of common mental disorders. In this work, a new polymer lab-on-a-chip (LOC) based on a microfluidic capillary flow assay (MCFA) with on-chip dried reagents was newly developed and fully characterized for the detection of unbound cortisol in saliva. The new MCFA device consisted of serially connected microchannels for sample loading, dried detection antibodies, time delay for incubation time control, a spiral reaction chamber for testing, positive and negative controls, and a capillary pump for waste fluid collection. In addition, a portable fluorescence analyzer was also developed for the rapid quantitative measurement of salivary cortisol with high accuracy. A linear dynamic range of 7.0 pg mL-1-16.0 ng mL-1 was achieved from spiked artificial saliva samples with an inter-chip CV of around 4.0% using the developed LOC and fluorescence analyzer. The achieved results support the effective biochemical analysis of common mental disorders such as chronic stress, depression, anxiety and post traumatic stress disorder (PTSD). The new LOC based on a microfluidic capillary flow assay (MCFA) developed in this work can be one of the most promising LOC platforms for high-sensitivity and quantitative POCT with saliva and blood plasma/serum samples.
唾液中的游离皮质醇可通过非侵入性采样进行检测，目前被认为是常见精神障碍生化评估中最有效的生物标志物之一。在这项工作中，一种基于微流控毛细管流动分析（MCFA）并带有芯片上干燥试剂的新型聚合物芯片实验室（LOC）被新开发出来，并对其检测唾液中游离皮质醇的性能进行了全面表征。新型MCFA装置由串联连接的微通道组成，用于样品加载、干燥的检测抗体、用于控制孵育时间的延时、用于测试的螺旋反应室、阳性和阴性对照以及用于收集废液的毛细管泵。此外，还开发了一种便携式荧光分析仪，用于高精度快速定量测量唾液皮质醇。使用所开发的LOC和荧光分析仪，加标的人工唾液样品实现了7.0 pg mL-1至16.0 ng mL-1的线性动态范围，芯片间变异系数约为4.0%。所取得的结果支持对慢性应激、抑郁症、焦虑症和创伤后应激障碍（PTSD）等常见精神障碍进行有效的生化分析。这项工作中开发的基于微流控毛细管流动分析（MCFA）的新型LOC可能是用于唾液和血浆/血清样品的高灵敏度和定量即时检测最有前景的LOC平台之一。
