Potentiometric sensors induce a spontaneous voltage that indicates ion activity in real time. We present here an advanced self-powered potentiometric sensor with memory. Specifically, the approach allows for one to record a deviation from the analyte’s original concentration or determine whether the analyte concentration has surpassed a threshold in a predefined time interval. The sensor achieves this by harvesting energy in a capacitor and preserving it with the help of a diode. While the analyte concentration is allowed to return to an original value following a perturbation over time, this may not influence the sensor readout. To achieve the diode function, the sensor utilizes an additional pair of driving electrodes to move the potentiometric signal to a sufficiently high base voltage that is required for operating the diode placed in series with the capacitor and between the sensing probes. A single voltage measurement across the capacitor at the end of a chosen time interval is sufficient to reveal any altered ion activity occurring during that period. We demonstrate the applicability of the sensor to identify incurred pH changes in a river water sample during an interval of 2 h. This approach is promising for achieving deployable sensors to monitor ion activity relative to a defined threshold during a time interval with minimal electronic components in a self-powered design.

中文翻译：

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具有记忆功能的自供电电位传感器

电位传感器感应自发电压，实时指示离子活动。我们在此展示了一种具有存储器的先进自供电电位传感器。具体而言，该方法允许人们记录与分析物原始浓度的偏差或确定分析物浓度是否已在预定时间间隔内超过阈值。传感器通过在电容器中收集能量并在二极管的帮助下保存能量来实现这一点。虽然随着时间的推移，分析物浓度可以在扰动后恢复到原始值，但这可能不会影响传感器读数。实现二极管功能，传感器利用一对额外的驱动电极将电位信号移动到足够高的基极电压，这是操作与电容器串联放置的二极管以及传感探头之间所需的。在选定时间间隔结束时电容器两端的单次电压测量足以揭示在该期间发生的任何改变的离子活动。我们证明了传感器在 2 小时间隔内识别河水样品中发生的 pH 变化的适用性。这种方法有望实现可部署的传感器，以在自供电设计中使用最少的电子元件在时间间隔内监测相对于定义阈值的离子活动。在选定时间间隔结束时电容器两端的单次电压测量足以揭示在该期间发生的任何改变的离子活动。我们证明了传感器在 2 小时间隔内识别河水样品中发生的 pH 变化的适用性。这种方法有望实现可部署的传感器，以在自供电设计中使用最少的电子元件在时间间隔内监测相对于定义阈值的离子活动。在选定时间间隔结束时电容器两端的单次电压测量足以揭示在该期间发生的任何改变的离子活动。我们证明了传感器在 2 小时间隔内识别河水样品中发生的 pH 变化的适用性。这种方法有望实现可部署的传感器，以在自供电设计中使用最少的电子元件在时间间隔内监测相对于定义阈值的离子活动。