Carter Liam, Nightingale Adrian, Feelisch Martin, Niu Xize
Mechanical Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, U.K.
Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton, Southampton SO16 6YD, U.K.
Anal Chem. 2025 Feb 11;97(5):2678-2688. doi: 10.1021/acs.analchem.4c04163. Epub 2025 Jan 27.
Total free thiols are an important marker of the whole-body redox state, which has been shown to be associated with clinical outcome in health and disease. Recent investigations have suggested that increased insight may be gained by monitoring alterations of redox state in response to exercise and hypoxia and to monitor redox trajectories in disease settings. However, conducting such studies is challenging due to the requirement for repeated venous blood sampling and intensive lab work. Droplet microfluidic sensors offer an alternative platform for developing a point-of-care testing approach using small sample volumes and automated systems to complement or ultimately replace laboratory testing. Here we developed a small, portable droplet microfluidic sensor that can measure total free thiol concentrations in 20 μL human plasma (or serum) samples, providing a reading in less than 10 min. This system features a novel method to enhance the mixing of reagent and analyte in droplets containing viscous biological fluids. The results in a range of real-world human plasma samples showed equivalence with current standard laboratory assays while reducing sample volume requirements 9-fold and fully automating the process. Micro hematocrit capillaries allowed testing of capillary blood samples collected by fingerprick lancing. The system was used to monitor total free thiols using fingerprick samples in healthy volunteers and revealed significant changes in total free thiols in response to food intake and exercise. This device has the potential to improve our ability to conduct physiological studies of total free thiol level changes and improve our understanding of redox physiology, which may ultimately be applied in redox medicine to improve patient care.
总游离巯基是全身氧化还原状态的重要标志物，已证明其与健康和疾病状态下的临床结果相关。最近的研究表明，通过监测运动和缺氧引起的氧化还原状态变化以及在疾病环境中监测氧化还原轨迹，可能会获得更多的见解。然而，由于需要重复采集静脉血样和进行大量实验室工作，开展此类研究具有挑战性。微滴微流控传感器提供了一个替代平台，可利用小样本量和自动化系统开发即时检测方法，以补充或最终取代实验室检测。在此，我们开发了一种小型便携式微滴微流控传感器，可测量20μL人血浆（或血清）样本中的总游离巯基浓度，在不到10分钟内给出读数。该系统具有一种新颖的方法，可增强含有粘性生物流体的微滴中试剂与分析物的混合。一系列实际人血浆样本的检测结果表明，该方法与当前标准实验室检测等效，同时将样本量需求降低了9倍，并实现了过程的完全自动化。微量血细胞比容毛细管可用于检测通过手指采血针刺采集的毛细血管血样本。该系统用于监测健康志愿者手指采血样本中的总游离巯基，并揭示了进食和运动后总游离巯基的显著变化。该设备有潜力提高我们开展总游离巯基水平变化生理学研究的能力，并增进我们对氧化还原生理学的理解，最终可能应用于氧化还原医学以改善患者护理。
