A potentiometric sensor interface consisting of a high input impedance programmable-gain preamplification stage followed by a continuous-time delta–sigma ADC is presented. To facilitate the integration into low-cost point-of-care (PoC) diagnostics, wireless power transfer (WPT) is used for powering of the sensor interface. Consequently, the wireless operation requires an implementation with high interference robustness. For this purpose, a fully differential topology of the potentiometric sensor interface is proposed, which achieves high robustness to interference in the power supply and signal path.