Wearable devices have received tremendous interests in human sweat analysis in the past few years. However, the widely used polymeric substrates and the layer-by-layer stacking structures greatly influence the cost-efficiency, conformability and breathability of the devices, further hindering their practical applications. Herein, we report a facile and low-cost strategy for the fabrication of a skin-friendly thread/paper-based wearable system consisting of a sweat reservoir and a multi-sensing component for simultaneous in situ analysis of sweat pH and lactate. In the system, hydrophilic silk thread serves as the micro-channel to guide the liquid flow. Filter papers were functionalized to prepare colorimetric sensors for lactate and pH. The smartphone-based quantitative analysis shows that the sensors are sensitive and reliable. Although pH may interfere the lactate detection, the pH detected simultaneously could be employed to correct the measured data for the achievement of a precise lactate level. After being integrated with a hydrophobic arm guard, the system was successfully used for the on-body measurement of pH and lactate in the sweats secreted from the volunteers. This low-cost, easy-to-fabricate, light-weight and flexible thread/paper-based microfluidic sensing device may hold great potentials as a wearable system in human sweat analysis and point-of-care diagnostics.

中文翻译：

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基于线程/纸张的可穿戴系统的简便，低成本制造，可同时检测人汗液中的乳酸和pH

在过去的几年中，可穿戴设备在人体汗液分析中引起了极大的兴趣。然而，广泛使用的聚合物基底和逐层堆叠结构极大地影响了装置的成本效率，适形性和透气性，进一步阻碍了它们的实际应用。在本文中，我们报告了一种简便且低成本的策略，用于制造对皮肤友好的基于线/纸的可穿戴系统，该系统由汗液储存器和多感测组件组成，可同时进行汗液pH和乳酸的原位分析。在该系统中，亲水性丝线充当微通道以引导液体流动。对滤纸进行功能化以制备用于乳酸和pH的比色传感器。基于智能手机的定量分析表明，传感器灵敏可靠。尽管pH值可能会干扰乳酸盐的检测，但同时检测到的pH值可用于校正测量数据以实现精确的乳酸盐水平。与疏水性护臂集成后，该系统成功用于人体从志愿者分泌的汗液中的pH和乳酸的体内测量。这种低成本，易于制造，重量轻且基于线/纸的柔性微流体传感设备可能具有巨大的潜力，可作为人体汗液分析和即时诊断中的可穿戴系统。该系统已成功用于人体从志愿者分泌的汗液中的pH和乳酸的体内测量。这种低成本，易于制造，重量轻且基于线/纸的柔性微流体传感设备可能具有巨大的潜力，可作为人体汗液分析和即时诊断中的可穿戴系统。该系统已成功用于人体从志愿者分泌的汗液中的pH和乳酸的体内测量。这种低成本，易于制造，重量轻且基于线/纸的柔性微流体传感设备可能具有巨大的潜力，可作为人体汗液分析和即时诊断中的可穿戴系统。