Wearable sweat monitoring represents an attractive opportunity for personalized healthcare and for evaluating sports performance. One of the limitations with such monitoring, however, is water layer formation upon cycling of ion-selective sensors, leading to degraded sensitivity and long-term instability. Our report is the first to use chemical vapor deposition-grown, three-dimensional, graphene-based, gradient porous electrodes to minimize such water layer formation. The proposed design reduces the ion diffusion path within the polymeric ion-selective membrane and enhances the electroactive surface for highly sensitive, real-time detection of Na⁺ ions in human sweat with high selectivity. We obtained a 7-fold enhancement in electroactive surface against 2D electrodes (e.g., carbon, gold), yielding a sensitivity of 65.1 ± 0.25 mV decade^–1 (n = 3, RSD = 0.39%), the highest to date for wearable Na⁺ sweat sensors. The on-body sweat sensing performance is comparable to that of ICP-MS, suggesting its feasibility for health evaluation through sweat.

中文翻译：

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利用梯度多孔石墨烯基板作为固体接触层提高可穿戴电化学汗液传感器的灵敏度

可穿戴汗液监测为个性化医疗保健和评估运动表现提供了一个有吸引力的机会。然而，这种监测的限制之一是离子选择性传感器循环时水层的形成，导致灵敏度下降和长期不稳定性。我们的报告是第一个使用化学气相沉积生长的三维石墨烯基梯度多孔电极来最小化这种水层形成的报告。所提出的设计减少了聚合物离子选择性膜内的离子扩散路径，并增强了电活性表面，以实现高灵敏度、实时检测 Na ⁺人体汗液中的离子具有高选择性。我们获得了 7 倍的电活性表面对 2D 电极（例如碳、金）的增强，产生了 65.1 ± 0.25 mV 十倍频^–1（n = 3，RSD = 0.39%）的灵敏度，这是迄今为止最高的可穿戴 Na ⁺汗液传感器。人体汗液传感性能与 ICP-MS 相当，表明其通过汗液进行健康评估的可行性。