School of Textile Science and Engineering, Tiangong University, Tianjin 300387, China.
Lab Chip. 2021 Mar 9;21(5):916-932. doi: 10.1039/d0lc01075h.
Flexible biosensors for monitoring systems have emerged as a promising portable diagnostics platform due to their potential for in situ point-of-care (POC) analytic devices. Assessment of biological analytes in sweat can provide essential information for human physiology. Conventional measurements rely on laboratory equipment. This work exploits an alternative approach for epidermal sweat sensing and detection through a wearable microfluidic thread/fabric-based analytical device (μTFAD). This μTFAD is a flexible and skin-mounted band that integrates hydrophilic dot-patterns with a hydrophobic surface via embroidering thread into fabric. After chromogenic reaction treatment, the thread-embroidered patterns serve as the detection zones for sweat transferred by the hydrophilic threads, enabling precise analysis of local sweat loss, pH and concentrations of chloride and glucose in sweat. Colorimetric reference markers embroidered surrounding the working dots provide accurate data readout either by apparent color comparison or by digital acquirement through smartphone-assisted calibration plots. On-body tests were conducted on five healthy volunteers. Detection results of pH, chloride and glucose in sweat from the volunteers were 5.0-6.0, 25-80 mM and 50-200 μM by apparent color comparison with reference markers through direct visual observation. Similar results of 5.47-6.30, 50-77 mM and 47-66 μM for pH, chloride and glucose were obtained through calibration plots based on the RGB values from the smartphone app Lanse®. The limit of detection (LOD) is 10 mM for chloride concentration, 4.0-9.0 for pH and 10 μM for glucose concentration, respectively. For local sweat loss, it is found that the forehead is the region of heavy sweat loss. Sweat secretion is a cumulating process with a lower sweat rate at the beginning which increases as body movement continues along with increased heat production. These results demonstrate the capability and availability of our sensing device for quantitative detection of multiple biomarkers in sweat, suggesting the great potential for development of feasible non-invasive biosensors, with a similar performance to conventional measurements.
用于监测系统的柔性生物传感器由于其在现场即时（POC）分析设备中的潜力而成为一种很有前途的便携式诊断平台。评估汗液中的生物分析物可以为人体生理学提供重要信息。传统的测量方法依赖于实验室设备。这项工作利用了一种替代方法，通过可穿戴微流体制动器/织物基分析装置（μTFAD）进行表皮汗液传感和检测。这种 μTFAD 是一种灵活的、贴肤的带，通过将线绣入织物中，将亲水点图案与疏水面集成在一起。经过显色反应处理后，绣线图案作为通过亲水线转移的汗液的检测区域，能够精确分析局部汗液损失、汗液的 pH 值以及氯离子和葡萄糖浓度。绣在工作点周围的比色参考标记通过明显的颜色比较或通过智能手机辅助校准图的数字采集提供准确的数据读出。在五名健康志愿者身上进行了体内测试。通过与参考标记进行直接目视比较，通过表观颜色检测志愿者汗液中的 pH 值、氯离子和葡萄糖的检测结果分别为 5.0-6.0、25-80 mM 和 50-200 μM。通过智能手机应用程序 Lanse® 基于 RGB 值获得的校准图，获得了类似的 pH 值、氯离子和葡萄糖的结果 5.47-6.30、50-77 mM 和 47-66 μM。氯离子浓度的检测限（LOD）为 10 mM，pH 值为 4.0-9.0，葡萄糖浓度为 10 μM。对于局部汗液流失，发现额头是大量出汗的区域。汗液分泌是一个累积过程，开始时汗液分泌率较低，随着身体运动的继续和产热的增加而增加。这些结果表明，我们的传感设备具有用于汗液中多种生物标志物的定量检测的能力和可用性，表明开发具有类似传统测量性能的可行非侵入性生物传感器具有巨大潜力。
