Figure 3.

(A) The principle of operation for the sensor where the nanomembrane demonstrates preferential permeability for anions at low-pH and for cations at high-pH. (B(I)) Current-voltage characterization of the sensor at varying pH values. (B(II)) The dependence of the current on pH at 600 mV. (C) The pH dependence of media in the buffer (gray) and inside the hydrogel (blue) at a distance from hydrogel surface for (I) hydrogel with initial pH value of 4.8 that was filled with buffer (pH 4.8) and (II) hydrogel with initial pH value of 4.8 that was filled with buffer (pH 7.3).