Biosensors that detect analytes in sweat face the challenge of maintaining sensitivity upon miniaturization. Various materials and processes have been developed to create nanostructured electrodes with high surface areas to mitigate this issue. The need remains, however, for biocompatible materials that can be scalably integrated into wearable devices. This paper details a gold thin‐film electrode fabricated using a thermoplastic shape memory polymer to create hierarchical wrinkled structures via the miniaturization process, followed by transfer onto a soft, stretchable substrate. The final stretchable electrode, which is ≈30 times smaller than that of the original, unshrunk electrode, retains its original surface area. Even more remarkably, further enhancement in current density is achieved upon stretching the electrode to 210% of its original length; improved sensitivity remains stable after relaxation of the polymer. Stretching aids diffusion limited reactions, such as the reduction and oxidation of [Fe(CN)₆]^3−/4−. The stretchable electrodes sensitively detect glucose without enzymes or additional labels at physiological pH in the range of 1 × 10⁻⁷–1 × 10⁻⁴ m with a calculated limit of detection of 2.22 × 10⁻⁸ m, among the lowest reported for a flexible, enzyme‐free sensor.

中文翻译：

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用于纳摩尔葡萄糖检测的可拉伸传感器

检测汗液中分析物的生物传感器面临着在小型化时保持灵敏度的挑战。已经开发出各种材料和工艺来产生具有高表面积的纳米结构电极以减轻该问题。然而，仍然需要能够可缩放地集成到可穿戴设备中的生物相容性材料。本文详细介绍了使用热塑性形状记忆聚合物制造的金薄膜电极，该电极通过微型化工艺产生分层的褶皱结构，然后转移到柔软的可拉伸基材上。最终的可拉伸电极比原始未收缩的电极小约30倍，保留了其原始表面积。更显着的是 将电极拉伸至其原始长度的210％后，电流密度会进一步提高；聚合物松弛后，改进的灵敏度保持稳定。拉伸助长了扩散受限的反应，例如[Fe（CN）的还原和氧化₆ ] ^{3− / 4−}。可伸展电极在生理pH范围为1×10 ^-7 –1×10 ^-4 m的情况下灵敏地检测到没有酶或其他标记的葡萄糖，计算出的检出限为2.22×10 ^-8 m，在报道的最低水平灵活的无酶传感器。