Quantitively and stably tracking ion dynamics in the living brain of animals is essential to understanding many physiological and pathological processes. Solid-state ion-selective electrodes (ISEs) are powerful tools for monitoring the dynamic change of ions at physiological concentration range; however, the unintentional accumulation of an aqueous layer at the ion selective membrane/ solid contact interface compromises the electrode potential stability, limiting its in vivo application. Here, using manganese dioxide (MnO₂) and potassium ISE (K⁺-ISE) as model solid contact and ISEs, we demonstrate for the first time that graphdiyne oxide (GDYO) can enhance the potential stability of solid contact-based ISEs. Our results suggest that the intrinsic structural and hydrophobic features of GDYO, plays a key role in impeding and stabilizing the formation of water layer. With GDYO-MnO₂ acting as the solid contact, the K⁺-ISE displays an excellent short-term potential stability and maintains great selectivity, achieving reliable K⁺ sensing at the animal level. The GDYO-based strategy is generalizable to different ISEs and does not require complicated processing steps, paving an exciting opportunity for in vivo ion recognition and sensing.

定量和稳定地跟踪动物活体大脑中的离子动力学对于理解许多生理和病理过程至关重要。固态离子选择电极（ISE）是监测生理浓度范围内离子动态变化的强大工具。然而，水层在离子选择性膜/固体接触界面的无意积累会损害电极的电势稳定性，从而限制了其在体内的应用。在这里，使用二氧化锰（MnO ₂）和钾ISE（K ⁺-ISE）作为模型固体接触和ISE，我们首次证明氧化石墨烯（GDYO）可以增强基于固体接触的ISE的潜在稳定性。我们的结果表明，GDYO的固有结构和疏水特性在阻止和稳定水层的形成中起着关键作用。使用GDYO-MnO ₂作为固体触点，K ⁺ -ISE表现出出色的短期电势稳定性，并保持很高的选择性，从而在动物水平上实现了可靠的K ⁺感测。基于GDYO的策略可推广到不同的ISE，并且不需要复杂的处理步骤，为体内离子识别和传感创造了令人兴奋的机会。