Sweat pH offers a plethora of physiological information as a routine parameter for health monitoring. Commonly-used organic H+-sensitive materials encounter a challenge of the biotoxicity in wearable sensing application. MoO3 exhibits biocompatibility and cost-effectiveness but limited by the electronic conductivity and ion diffusion capacity. Lattice proton intercalation is herein proposed to prepare an electron–proton hybrid conductor of HxMoO3 for potentiometric pH sensing. The intercalated HxMoO3 established efficient proton transfer channel and reduced the charge transfer and proton diffusion resistances, thereby significantly enhancing the proton-coupled-electron transfer reaction. Reversible proton transfer in the lattices of HxMoO3 realized a Nernstian sensitivity and high selectivity for H+. Finally, an integrated flexible pH sensor based on HxMoO3 and solid-contact reference electrode has realized on-body monitoring of sweat pH. This work proposed a concept of lattice proton intercalation as an efficient strategy for structural manipulation of metal oxides, thereby enhancing their potentials toward sensing applications.

中文翻译：

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HxMoO3 的电子-质子杂化导体用于汗液 pH 值监测


汗液 pH 值提供了大量的生理信息，作为健康监测的常规参数。常用的有机 H+ 敏感材料在可穿戴传感应用中遇到了生物毒性的挑战。MoO3 表现出生物相容性和成本效益，但受到电子电导率和离子扩散能力的限制。本文提出晶格质子插层以制备 HxMoO3 的电子-质子杂化导体，用于电位 pH 传感。插层的 HxMoO3 建立了高效的质子转移通道，降低了电荷转移和质子扩散电阻，从而显著增强了质子耦合电子转移反应。HxMoO3 晶格中的可逆质子转移实现了 H+ 的 Nernstian 敏感性和高选择性。最后，基于 HxMoO3 和固体接触参比电极的集成柔性 pH 传感器实现了汗液 pH 值的人体监测。这项工作提出了晶格质子嵌入的概念，作为金属氧化物结构操纵的有效策略，从而提高了它们在传感应用中的潜力。