Potentiometric sensors operate as galvanic cells where the voltage is spontaneously generated as a function of the sample composition. We show here that energy can be harvested, stored during the sensing process without external power, and physically isolated from the sensor circuit for later readout. This is accomplished by placing an electronic capacitor as a portable transduction component between the indicator and the reference electrode at the point where one would ordinarily connect the high-input-impedance voltmeter. The voltage across this isolated capacitor indicates the originally measured ion activity and can be read out conveniently, for example, using a simple handheld multimeter. The capacitor is shown to maintain the transferred charge for hours after its complete disconnection from the sensor. The concept is demonstrated to detect the physiological concentrations of K⁺ in artificial sweat samples. The methodology provides a readout principle that could become very useful in portable form factors and opens possibilities for potentiometric detection in point-of-care applications and inexpensive sensing devices where an external power source is not desired.

中文翻译：

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自供电电位传感器转换为电容式电子元件，以供以后读出。

电位传感器用作原电池，其中电压根据样品成分自动产生。我们在这里表明，可以在不使用外部电源的情况下收集，存储感测过程中的能量，并将其与传感器电路物理隔离以供以后读取。这是通过在指示器和参考电极之间通常会连接高输入阻抗电压表的位置放置一个作为便携式转换组件的电子电容器来实现的。隔离电容两端的电压表示最初测得的离子活度，可以方便地读出，例如使用简单的手持式万用表。如图所示，电容器与传感器完全断开连接后，可以保持转移电荷数小时。⁺在人工汗液样本中。该方法提供了一种读出原理，该原理在便携式外形尺寸中可能会变得非常有用，并为不需要外部电源的即时医疗应用和廉价感应设备中的电位检测提供了可能性。